Build A Hardware Store Race Car. Or Just Watch Me Do It. Whatever.

[@SuperfastMatt]

Go to ground.news/superfastmatt to compare news coverage and spot media bias. Subscribe through my link for 40% off unlimited access this month.

[@SpaceMulva]

Does ground news feature stories from any sources that are anti-israel?

[@TheStuartstardust]

0:53 i feel like we missed out on a truss bridge jokes here, given recent events..

[@charlieg4113]

Love this choice of sponsor! I already pay them, but maybe I should sign up and pay for another account just for you... 🤔

[@michaelblacktree]

Sanding latex paint is gonna be fun. (sarcasm) But I've had good results with polyurethane, and also with epoxy resin. When it dries, it's harder than the foam. So you have to be careful not to sand through it. Edit: Also make sure to knock down any high spots in the foam BEFORE applying the surface coating. Low spots aren't such a big deal, because you can fill them later.

[@nobodynoone2500]

CNBC as centrist... LMAO. Dude at least do basic diligence on the companies you promote.

[@SidewaysGts]

I expected: "There is the difficult cheap way, and an easy expensive way. And my way, which is both difficult and expensive"

[@darekmistrz4364]

We all know that any cheap way is an expressway to finding out why expensive way is the right way.

[@theleva7]

Everyone who tried to DIY anything ever knows that the road to easy and cheap way is paved with multiple should've-been-easy-and-cheap-way remnants

[@somedude2492]

It will be. Give it a month.

[@AHSEN.]

​@@theleva7 Yes. :(

[@troycongdon]

The easy/cheap way gets the job done. Learning how to do it the right way is expensive because education is not free. When he is done he will be able to do it cheap for the next project. It is like buying tools. It may be cheaper to pay someone else for this job but it is better in the long run to buy the tools and do it yourself.

[@WeAreChecking]

Hey Matt, hopefully this doesn't get too lost in the sea of comments, but back when I was working on the aero department of my FSAE team we had excellent results using foam molds with spray-on gelcoat on top. Makes for a really nice surface finish and (potentially critically) a really durable mold so should the unfortunate happen and you crack a fiberglass part you don't have a damaged mold from the first part and can just lay up another part. Plus it's really easy to get a nice full coverage of the foam so it sands nice and even. A real tip is to use different colors for each coat so when you're sanding you have a visual indicator of when you're getting too close to the foam underneath. Lastly, it might be worth looking into some basic metrology, once you're done with the first part, it may be a good idea to 3D scan it and compare it with what you were intending to make. Mold making is a real pain and it's easy for tolerance stacking to cause some real aero headaches that feel impossible to diagnose - ask me how I know. Anyhow, really dig the content. Godspeed on the build, and I'd be more than happy to give any other advice on composites/aero if you're coming up against a particularly annoying hurdle.

[@BloomingtonFPV]

This is good advice. Also consider duratec grey surface primer

[@anonathan]

Nice name, I understood that reference

[@SuperfastMatt]

Thanks for the info. There are a couple of parts that I will need to pull an actual mold off of, so I might try the gel coat spray with those.

[@Andrew_Fernie]

@@anonathan Box, box. Stay out! Stay out!

[@danielwoodard680]

Dear algorithm, please give this random-contributor-guy a bump in case he ever returns

[@taylorgriffin7468]

"...the front needs to be done well. So I am starting at the back..." SuperfastMatt is my spirit animal.

[@joelaw728]

Try on an inconspicuous area first

[@Wheagg]

Well, it's actually fairly smart if you think about it. Fucking up the back end isn't as big of a deal, by the time he makes it to the front he should be rather good at this. It's 100% procrastination, though

[@trevorjansen4102]

Anyone who's tried building anything themselves and been humbled would agree with the approach 😂

[@jamesharwell9171]

I used to work for a small aerospace engineering company and we built stuff the exact same way. Some of it even made it into space.... on purpose.

[@brianhaygood183]

At 1:15, I like how the "engine explodes" and "250mph" statement encompasses both the optimism and pessimism of racing.

[@dustinbaird1008]

I actually laughed out loud at that statement.

[@mr_voron]

Man, I’m glad you added Barby vomit extraction before that top radiator got fully clogged and your spindle explosively divorced your CNC

[@NickCohn]

Thanks, Matt, for making mistakes so that we don't have to 😉

[@oraziovescovi1922]

I haven't watched the video yet, but judging by this comment, it'll be a wild ride

[@timplett1]

@@oraziovescovi1922 is there any SuperfastMatt video that ISN'T a wild ride?

[@dougm2745]

I worked with a R+D composite fabricator who started each of our projects with a trip to Home Depot for insulating foam. No degree no formal education, just smart. Of course they laid him off when money got tight…He obviously landed on his feet.

[@bw1532]

Matt, you are an inspiration. Not because of your racing, or your videography. You are an inspiration because of your transparency and your troubleshooting abilities. Your troubleshooting abilities might actually be in the god-damned-hero category. The transparency is in the everyone-should-do-this-but-humans-suck-and-therefore-dont category. I appreciate that you are extremely honest about your mistakes and show us the whole process because that is honest and real.

[@DJDiarrhea]

I recently rewatched some old videos of ThisOldTony. Notably his 3D Printing video, where he built a 3d printer on a surface plate, leveling it out with shim stock to get all the rails square and parallel. Quite the contrast to Matt who runs his CNC router off a piece of wood, fastened to the wall and supported by a single post. Love it!

[@cosmic_cupcake]

funnily enough I just started poking my head into custom 3D-printer building, and when I saw Matt disassemble and the reassemble his router I immediately thought "hold on, he´s not squaring anything!" But halfassery is basically the unofficial name for this channel so I can´t say that I am surprised lol.

[@Chaos_God_of_Fate]

If you think this is janky you should see my laser engraver/cutter setup! It's pretty hacksy but it works very well. With enough Cardboard, duck tape and hot glue you can make most anything!

[@SlinkyD]

3 points make a plane. Unless they changed school again, then IDK. Imma Toys'R Us guy.

[@DJDiarrhea]

​@@SlinkyD 3 points do make a plane, but wood doesn't make for an exceedingly rigid frame

[@dmacpher]

The fast cheap good triangle strikes again!

[@scottcates]

I'm in awe of his troubleshooting the problem(s) though. Here is my CAD face🐵

[@petergamache5368]

It's only through practical experience that one learns the "pick two" part of that mantra doesn't mean you'll actually get those two ... or even one.

[@MrRedstoner]

@@petergamache5368 Yeah it's best stated along the line of "at most 2" rather than promising 2

[@name-less817]

No ham sandwiches were harmed in the making of this video

[@JordanKeller]

Based factorio enjoyer

[@swat1229]

Disappointed

[@TheShootingBrake]

Painted a lot of this foam in architecture school. You can paint it with anything, but you have to hold the can at least 6-8” away from the foam. This allows the solvent in the paint to evaporate before hitting the foam and melting it. Takes more paint, but it is the way to do it.

[@ItsDaJax]

I was looking into this foam to make models and sculptures, so that's good to know. Is there anything out there one can use to harden it, like is it porous enough to absorb something to harden it, or would paint be good enough? Because I briefly was looking at a thrown out couch and had to talk myself down from using the cushion to use because that foam is so soft, that I would need something for it to absorb and harden as I shaped it.

[@lassikinnunen]

​@@ItsDaJaxyou'd need open cell foam to get epoxy or something to not stop at the surface.

[@bake162]

Nice of you to share the foam with the neighbors

[@danielwgk]

hey Matt, the eats-away-foam or doesnt-eat-away-foam comes from the solvents in the paint/coating. the trick we use is to spray from further away so the solvent flashes off by the time the paint gets to the foam. also, light coats so it flashes off on the surface, not soaks into the material. hope you read this and i hope it helps.

[@kingnull2697]

Damn, thats' a good hack if it works

[@TerranCmdr]

@@kingnull2697 Can confirm we used this technique on large foam props. For most of them though we applied a 'hard coat' barrier before spraying.

[@cafn8ed74]

If you are a broke Industrial Design student, you can form pink foam with surform tools. It's less dusty than sanding. Static will still turn you into a pink snow monster.

[@D3nn1s]

As a broke industrial design student i approve of this message.

[@cafn8ed74]

@@D3nn1s been there.

[@allareasindex7984]

Pink snow control musing: High voltage /low current plate to attract snow. Just a hasty, incomplete thought. You know, like engineering design.

[@D3nn1s]

@@cafn8ed74 youre doing ID full time now?

[@cafn8ed74]

@@D3nn1s nah, engineering for the last twentysomething years. The skills translated well enough and from there I learned what I needed as I went along.

[@paulnielsen8528]

Many years ago I ran the department, no, I was the department making expanded polyurethane caskets. No respiratory protection. Washed my hands with Methyline chloride to remove the sticky crap at the end of the day. I'm 68 and amazed I'm alive and don't have cancer or emphysema. And thrilled to see the nifty stuff a cool mind like yours makes with modern technology. And humour. Thank you for what you give to society man.

[@TheThunderwars]

11:33 "Respectfully, may I ask if you are on the spectrum" I spit out my coffee.

[@lazerlight5155]

Im like 70% sure my dude has adhd

[@JSG1901]

"Moldless construction." I built an entire carbon fiber Porsche Boxster body this way but I didn't know that's what it was called. Thanks for the new term! Love your channel, BTW.

[@EllipsisAircraft]

Burt Rutan coined the term with his aircraft designs from around 1968 onward. The technique was adopted from RC pylon racing aero-modelers, and sailplane repair shops. Who used foam as internal backing for composite repairs.

[@piscinabuquet9936]

Always a good day when there's a superfast Matt video

[@BenjaminT.Minkler]

I think people stress too much when making a 'buck' for a form: 1) they can be made out of anything, esp in the center if not just hollow(and by 'anything' I mean even bags of trash inside) the materials used and colors don't matter, as long as just the very surface is good; and it doesn't have to last long, cue the ham sandwich for this if anything 2) while the final shape here is important to accurately match your design, not all pieces have to be cut from solid full blocks(you could rough out most of the shapes in glued together scraps, and of course leave voids that aren't near the surface) think about all the material you needlessly wasted by just grinding it into so much dust - and once you have the tricky bits cut that must be right and define the shape, just slap boring mostly flat or smoothly curved(bent) thinner sheets on by eye to fill in-between(like the sides or top) and shape by hand with saw/files/sander 3) no need to have all the foam sheets stacked all in one orientation, if one area needs to be mostly flat just use a flat sheet going that way instead of trying to make a flat area from so many edges of stacked sheets, which would be much harder and the worse way to make and finish a flat from many different levels of edges and glue seams 4) caned spray foam is 'great stuff' to fill gaps and stick things together - to get around the mess use plastic sheet in-between the project and yourself/floor, and because the foam when cured doesn't stick to the plastic you can cover the growing foam with it and shape it nearly exactly how you want(vs out of control blobs) even adding layers of thinly spread foam squishing it around(thru the plastic) with your hands and small cardboard to get it totally smooth; this would be the "additive" method of sculpting vs only removing material and can fix any area where you removed too much 5) you aren't going to keep this part! this buck will either be a 'use once' as a positive mold and destroyed(or just left in), or used to make a negative mold to make multi parts from that - so no need to go nuts on the structure and strength, that only makes it harder to break apart and trash

[@thesuit4820]

Barbenhiemer. Your CNC has become the destroyer of foam. You're just Matt.

[@AraniaTwoFer]

0:46 As soon as I saw the lead screw being covered in foam dust I immediately knew that this is going to be difficult AND expensive

[@80spodcastchannel]

Hey Matt when your done..paint it gray, add a few flippers and tail, and sell it as a scale dolphin or whale model.. recoup your losses!!!!!

[@christianpowell1481]

11:34 - "Respectfully, may I ask if you're on the spectrum?" lmao

[@troycongdon]

Anyone watching this channel is on the spectrum…

[@jaggederest]

@@troycongdon Yeah I feel like it's one of those questions where, if you have to ask...

[@ciano5475]

@@troycongdon I am ✋🙂

[@thedude4795]

@@troycongdon the gender spectrum lol

[@darksu6947]

​@@thedude4795Do you suffer from having the big gheys?

[@mackmcmillan9905]

To make a fiberglass body for a racecar, you first need a mold..." ("And NOT the kind growing in my vertical stabilizer.") -Matt, probably

[@ofp8574]

It is nice to know that I am not the only one who ends up trying to do something a cheap and easy way and ends up spending more money and more time and energy than I would have doing basically anything else. Best way to look at that in my opinion, is to just know there would be unforseen problems with whatever route you took. Some people have lots of luck and everything works out for them every time. Some other people, you can put ten times the time and effort into something and have it all fall apart. It used to bother me, but I got used to it.

[@julianrossi8460]

The day we all wanted but never expected: the making of the body. Rejoice!

[@alekonicolacakis7002]

Well I have an engineering class rn but I guess I'll watch this instead, surely I will learn a similar amount

[@philipgrice1026]

Matt. You need to get a four axis laser alignment tool. They are now quite inexpensive, at least the Korean ones like I have. After wasting man months or even year of times with rulers tape measures and carpenters squares, one of my subcontractors gave me one when he upgraded. It is brilliant. Self leveling, use just the axis you need, or as many as required, lock it and rotate to handle non-square alignments, etc., etc. If you do, get a green laser, not a red one. The green is more visible in normal daylight, even outdoors, but not in bright sunlight. I think you'd need a military grade one for that. 😇

[@davidg3944]

Let us know the vendor and part numbers for your laser aligner? Thanks!

[@MrRyanTrott]

My favourite channel, perfect blend of engineering, automotive and entertainment.

[@bob.w3984]

Need to create a opposing charge on the foam or groud it all.

[@fatcamp907]

Matt, if you check with roofing companies in the area they might have left over foam from projects that they'd let to cheap. Come of the pieces can be really big, and are usually high density.

[@chrislee7817]

You could strengthen your router tube by running a wire down the center and tension it . If the wire is forced down at the centre point (slug of ally with an offset hole) it will add some upthrust. You can calibrate it with the amount of tension you put it under. 😊

[@fredygump5578]

Matt, the internet told me that I am dumb, because I spent a lot of money on a Shopsabre CNC and a proper dust collector. They said I should have bought a onefinity machine and a harbor freight dust collector and saved tons of money. So thanks for validating my decision to buy the real thing!

[@Strykenine]

Man, I have never seen someone who needs a 3 car garage more than Matt.

[@m0rph171]

Looking good! Latex paint should work well and then you can work with the cheaper poly or vinylester resin. You can drill a couple of holes for compressed air (put a pipe/straw in there) to help pop out the shell, plug them with wax or play-doh before you laminate. Any additional advantage is good. Use multiple thin layers of fiberglass rather than thick ones, easier to laminate with a roller. Sand the shell before popping it out by hand with a long flexible ply board with handles, hot glue or staple the sand papers. Sand systematically with long passes along the part, should be quite quick if you have the correct grit. Another way is to sand the whole body when all parts are installed, then you can do even longer passes with the sanding board tool. And in case you make a mold from a plug, careful with removal agents and gelcoat, the agent can cause spider web like defects, I prefer to use only wax. Spray-on removal agents are safer then brushing, but in any case don't use much. With only wax you can get a bit of a suction-cup effect, depends on the part.

[@Gunbudder]

the best way to make a mold is to go to Missouri in the summer, buy a loaf of fresh made bread from the bakery and put the loaf of bread in your cupboard. wait about 15 seconds, and you will have a nice loaf of mold.

[@billiefox1149]

I love this channel, it allows me to have realistic expectations in my projects

[@scottcates]

+1

[@sparrow082]

Spray your fome down with polycrylic before you use the wood filler. I got a $17 spray gun from Harbor Freight, and I use straight polycrylic. It takes two or three coats to get a decent hardness on the surface, but it only takes about 10 minutes to dry between coats in warm, dry air. Then you get a uniform sanding surface

[@freeidaho-videos]

I just signed up for Ground News, based on a single recommendation from some guy on the internet. I'm also an engineer and watch your videos because they are the quintessential combination of engineering skepticism, sarcasm, and persistence. One of my favorite sayings, that I made up is: My momma taught me that persistence pays off. The thing she forgot to tell me and I didn't know to ask was how damned slowly it pays off. Carry on!

[@oxide7]

I end up going down this same path on 90% of my projects. Start with the least important part cus you know you're doing something you have no business trying. Fail, learn, fail, learn, finally make it good enough. Can be a challenge to keep the spirits up sometimes haha.

[@wojciechbieniek4029]

When you've been assembling the mill, i've been thinking "how does he square the rails?" And when the pieces were misaligned it hit me, you didn't :) I'm glad you've been able to find the root of this problem

[@mrbuttons1243]

Years ago at my work our films department used a ton of that pink foam to make a fake log cabin set for a live stream event that was going to happen. They used a miter saw to make all the big cuts. 6 months later we were still finding pink dust everywhere on that floor.

[@amandahugankiss4110]

going to steal that vacuum hold-down system. looks perfect for me.

[@krazed0451]

Just buy a commercial vac bed if you need to be held down, ya kinky bastard 😂

[@rincam5]

definitely should invest some time in a metal table for that cnc machine 😂

[@MiniLuv-1984]

Nice one Freddy. If you could rotate the CNC head in two directions, then you could fit a hot knife in place of the router and save on all that foam dust/chips. Ofcourse, that means possibly new CNC software with more dimensions of freedom, wiring, motors and a 2D rotation assembly mounted in place of the router (I guess this would look like a universal joint?)

[@chrisreed3515]

Hey Matt - you might want to try light weight topping compound instead of regular drywall mud. It's noticeably softer and easier to sand.

[@camerone397]

neat stuff. Been watching my school's FSAE aero team do pretty much this for the last two months so this is an interesting alternate viewpoint. (Yes, we are behind.)

[@aaronb7990]

So much foam!!! That's one of those projects you remember 10 years from now when you find a pile of foam dust inside a box that was slightly cracked open. 😆🤙

[@owensparks5013]

You can also machine the foam under size, slather it in filler, then machine again at the correct size to get a hard shell.

[@christofschwarz6602]

@14:55: aaaaand thats the reason tooling foam exists :P It can also be coated with Automotive paint filler and sanded extra smooth, ....

[@Lunarmobiscuit]

Those separators don’t do well with sawdust either. My solution was a 32 gallon trash can, with the inlet as the separator, the outlet of the separator taped over, and a new outlet cut into the trash can lid. With that the dust has to make a 90 turn to leave the can, and at least for sawdust, most ends up at the bottom of the can. For the foam dust, I’d try covering the outlet hole with a piece of screen or a layer of paper/fabric from one of those vacuum trash bags. If this works the added benefit is 32 gallons of dust in a cheap plastic trash bag instead of 9-10 gallons in expensive vacuum trash bags.

[@EllipsisAircraft]

Try adding 10 gallons of water, the inlet then has a PVC pipe riser that forces dust down thru the water.

[@elektro3000]

I've been using that same HF shop vac for years (including for dust collection) and I agree, those bags make life SO much easier.

[@krashanb5767]

Do you reuse yours? They can be cut open for emptying.

[@elektro3000]

@@krashanb5767 I've actually just been dumping it out through the hole. Doesn't empty it 100% but I get it about 90% empty if I shake it.

[@isaacplaysbass8568]

Your solution serves as both inspiration, and an illustration of things to consider.

[@napalmholocaust9093]

One 24"/ 50 micron bag is like 15 bucks on ebay. My dust collector cost that, plus one ratchet strap to hold it to the base of an old shop vac with that diameter as the ring betweenthe bag and the fan. The rest was free stuff so milage varies. Its the fan that gets ya. My inline 6 with a 24" diameter came from a scaredy cat's clandestine greenhouse and probably cost 500 or more new.

[@ShawnChristopher10101]

I love your videos, they remind me that no matter how much practicum there is, experience is the real teacher.

[@hedrives]

Matt, I just LOVE your channel. As an ex-salt racer in caars and bikes, I'm really enjoying your streamliner build.

[@jonathantatler]

Always a good day when a 'SuperfastMatt' video pops up.

[@sideburnie]

kudos for publishing your struggles with CNC trueness and squareness. i'm about to get one, and i'm sure it'll save me a bunch of headache down the line.

[@leftfootfirst9847]

I use a shellac primer to seal the foam before pulling a part from it. It leaves a really hard candy shell that you can wax for mold release. Looking good tho!

[@andycollins8577]

If you think modelling foam is expensive , check out epoxy tooling board. Sure you can make carbon fiber heat cure parts directly in it but man it’s expensive!

[@cavedog1279]

Conventional milling has more tear-out, not climb. You're clearly using climb milling (in some of the shots, although now I'm seeing conventional in others) so I'm sure you know that, just wanted to clarify in case someone watching wants to learn a bit about cnc, which they definitely should. Climb milling is heavily discouraged on hand routers as it is inherently more dangerous, however a CNC does not care because it is a robot, so it is generally preferable to climb mill in most situations. Conventional milling is like trying to paddle a canoe as it is moving backwards through the water, the medium fights you the entire way. Climb milling is like paddling a canoe that is heading forward.

[@timplett1]

Depends on the material. I have (basically) the same CNC as he does and when cutting wood, conventional milling provides a noticeably better surface finish than climb.

[@tomcoon9038]

@@timplett1 As a toolmaker, I can attest to the fact that you are correct. To add to it, cutting plastics will "glue" the chips back onto the part behind the cutter when climb milling because of the heat. Same with aluminum unless coolant is used.

[@Shaaaaaaaaawn]

9:36 rctestflight has a bunch of nice videos on printed cyclone separators, he used it for "exploded barbie foam" aswell but his design was quite a bit wider

[@KarpucMotoring]

The vacuum trick for holding the foam is super neat...! Something about the way Matt talks makes the videos enjoyable to watch. Straight to the point and funny

[@haraldgrnvold5518]

You are one of the 4 sweetest guys (and top 2 sweetest engineers) I know, Matt. Thank you for being you, please don't stop.

[@SubTroppo]

Matt's succession of purchases and tooling needs remind me of the old 'Hole in the Bucket" song. The straw in the song leads me to wonder whether it is possible to carve bales of straw with a CNC machine. ps I should really check on KZbin before posting this comment but...

[@chrisschlis9440]

You're learning while we're learning AND being entertained. Thanks!

[@ejgrant5191]

Pretty AWESOME STUFF. My friend in the SF Bay Area Bob Wirth builds lots of SCTA Bonneville motors including bikes. His R&D shop is amazing and he told me the tale of a few years back about the "CnC Routing Method" to shaping the modern streemliners....I'm pretty sure the case he described was from a "bottomless checkbook" racer involved tens of thousands of $$$ in the design & shaping of the body. Your skills & innovations are amazing! Job well done! I'm sure you have a great handle on things but, if you ever start struggling with your powerplant....Bob is the MAN! His services and skills were employed during the AckAttack's record setting venture....Bob didn't build or design that machine, he was just brought in when they were struggling and made the best with what was there to work with. You can see bits of his AMAZING SHOP when they did "Dyno Testing" in the documentry that aired on the Discovery Channel.

[@lbgstzockt8493]

When tasked with the choice between the easy but expensive option and the cheap but hard one I tend to chose the hard and expensive one.

[@JWbrasser]

top tip for spray painting foam, use more distance, its actually dissolving in the propellant gas not the paint (unless its solvent based paint which would surprise me a little, a lot of those rattle cans are water based these days...)

[@GustafsonBen]

I don't do cars other than my 98 xj... but I do woodworking, and its nice to see someone else try to track down problems and fix them... there are always problems...

[@paulketchupwitheverything767]

I've got a production car with a fiberglass body and started using resin and matting for small repairs to it. Since then I've used it for adding a durable, contoured surface to various objects or for adding a strengthening backing or reinforcement to all kinds of things. I don't use a mold, as you should for a smooth finish. I paint some resin on to the surface, lay dry matting on then apply more resin onto it all. This avoids resin soaked matting from disintegrating when handling it. I then build up a few layers repeating the process and spray paint it once cured. I know it's not the recommended way of using the stuff to get maximum strength out of the material, but it has allowed me to repair plenty of things where gluing it wouldn't last and where a textured surface finish isn't essential.

[@corychristensen5917]

Extend your garage.... genius. The permits and supplies will be cheaper in the long run.. BTW I love your videos. Keep it up

[@nicholasvankley]

Matt, honestly you’ve pushed me in many ways..really appreciate your videos

[@Narwaro]

There is an easy, expensive way and a hard, cheap way. My way is both hard and expensive 💁‍♀

[@mrzmaster2]

Use vinyl on your mould for a nicer surface finish and release!

[@efeekinci3020]

9:10 When working with low density materials on cnc, using conventional milling strategy makes edges so much smother. Give it a try next time.

[@CreaminFreeman]

I only started watching your videos a little bit ago but I think your channel came at me right when I needed it. I’ve been sitting unmotivated to work on the project car. Today I marathoned a bunch of your videos starting from the bottom. Another thing I did today was paint the shift linkage on my project car. The thing I’ve been dreading (and I don’t know why) is putting the cables back on the A/C controls on the dash the same way they came back in. But hey, the shift linkage is painted so I’m basically almost done!

[@oikkuoek]

On any coat/fairing compound, always check the thinning and hardening agents. These are the ones reacting with your bulk medium. You can also add the barbie dust to an epoxy and apply that for harder edge, which can be later on faired with regular bondo. The epoxy goop has similar consistency as the bondo, so these two can be sanded to a smooth finish. Much more important bit is how you are going to 1. Attach this Speeldo to your existing structure so that it holds on both runs? Panel gluing bandages with threads sticking through is common, also this makes the skin flap in the breeze like used raincoat. It needs some sort of structure to stiffen it, and this needs to be designed into the mold. You can panel glue the inner structure to the outer skin, in fact this semi elastic bond edge holds best of all the options, but you still need the mating surface to be exact. 2. How are you going to attach these outer skin parts to each other? You need to machine every seam into the mold. Yes it's possible to hand craft these over lays afterwards, if you have 25 years of experience in hand carving precise mating surfaces. But after seeing your skill set, I whole heartedly suggest you design the mating surfaces of these pieces into your CAD, before you cut them out. Again, if you had simply pulled the car apart, added the attachment points to your frame, wrapped the frame in plastic/cardboard and sprayed two boxes of spray insulation on top of that, sanded, added some epoxy to the dust and plastered the mix back on, sanded again, another round of epoxy dust goop, sand, bondo, sand, latex, fiber glass, sand, bondo, sand, paint and done. Maybe a week. Real, successful land speed racers are all done by hand. This CAD/CNC nonsense is just a waste of time. When the effort is lost in spinning a virtual model around inside incomplete program, the essence of land speed racing is lost, and the end result will never be anywhere near the goal.

[@junkopotomus]

I do a lot of miniature modeling with XPS. The best route for painting would be to make a wash with Modge Podge, water and paint color of your choice. You can apply with a roller, or brush as it self levels pretty well. After that has dried, you can also now spray paint it for more even coverage and the solvents will not eat the away at it. I haven't made a 20 foot object before so there maybe some scaling in the procedure I haven't thought of.

[@Mart77]

Whoever is planning to cut polystyrene foam with hot wire - good receipe is 0.8mm wire with about 30V DC voltage. Wire gets just about right temperature to cut nicely.

[@marcfoster2260]

Matt, the table you have the CNC on is also surely contributing to your problems. No doubt it is warped. Consider a steel table top on C channel with 4 steel tube legs and levelers. You'll have less vibration, cleaner cuts, and less vacuum slippage so you can have a higher feed rate.

[@johnjuiceshipper4963]

Love seeing the exact same materials get used by miniature diorama KZbinrs and landspeed record KZbinrs.

[@AlexanderBurgers]

...I guess next up we will see plaster, brown paint, and PVA glue for static grass? :D

[@JosephMarkusic]

What I have found that works well with finishing the foam bucks or make molds is to coat with epoxy once you have the basic shape. I usually have really old stuff around that I don’t want to use for finished parts anyway. Then I use either 30 or 45 minute mud (the stuff in bags) which dries pretty fast and sands easy. When “done”, another coat of epoxy gets the finish close and and makes ti less likely to deform.

[@roi354]

I was about to say buy a cyclone but not the small one as the air velocity would be too fast to separate the foam from the air. But you did. Oh well. If you go out and buy a second cyclone, add it to a second bin, and adapt the vacuum duct so you split it into two before the cyclones, you'll likely be able to separate to your heart's content. There are duct calculations for this (I know, it's my job) but - without the hassle - if you can slow the suction enough to separate but still extract from the workpiece you'll have success.

[@DanBowkley]

3M Marine Acryl-White Glazing Putty. The stuff is amazing. Since you're using XPS the pore size is small enough that you won't use a ton of it, which is good since it's like $2/oz. But it sands like a really good dream. Definitely use it between the fiberglass body and the sanding primer before painting.

[@Panthera_Leo_]

Ok that vacuum work fixture thing is really clever, nice

[@jhuntosgarage]

Another good one, Matt. Learning and sharing helps everyone. I'm sure the algorithm would agree. Thanks!

[@IanLikesVideosSometimes]

I really dig your sponsor - hadn't heard of them before. Thank you for promoting good stuff, like Send Cut Send and Ground News!

[@MrZX1206]

There is a KZbin video where a guy mounts his Onefinity vertically to a wall. It seems like gravity would help clear the chips and it would take up less space.

[@AaronHendu]

Also...I spent good money playing with this foam and different adhesives...and I found Gorilla Glue type 2 water resistance the best for the price. A gallon is about $30 and it has held up to a full Canadian winter in the elements with zero lifting or ill effects. I used it to bond all the foam, and as the base adhesive for the poor man's fiberglass lamination process. I tested tightbond type 2, foam spray adhesive, several caulk gun tube adhesives and the cheap Gorilla glue worked as good as anything for far less $$$.

[@mcskifter]

Put the suck and blow sides of the vac into the tent. Keeps air moving and clears things fast. Add a little exhaust bypass to outside to keep the tent slightly negative pressure.

[@scottjones340]

When I square up my cnc plasma cutter, I just fix a pen to the torch (router in your case) mark/plot 4 points in a square, almost as big as you can move the axes e.g 500mm square. Then, just measure from corner to corner. If it's out, turn off the machine nudge it. Repeat until square.

[@justaeropaul]

im the aero lead for my schools sae team and we've been using 3m grey multipurpose duct tape as mold reliese. It works great for west systems 105 epoxy and ducttape is SOOO much cheaper than release films and teflon tape!!

[@bugjuicer]

Love these vids more, that you go in to just the right amount of detail, about why something f'd up and how you overcame that (and sometimes f up again). This is what YT content should be... Also helps me for learning things about my 'scheduled' projects

[@impossiblejonathan9650]

I'm so pleased to have the old outro back. Best outro ever. Keep up the good work ;)

[@bedlamite42]

10 seconds in I was expecting a joke about a ham sandwich sitting in the back of the garage for way too long.

[@scottcates]

SFM did not disappoint :D

[@TheRalliowiec]

You can "slightly" cut and snap XPS foam just like drywall, so no hot wire needed. Also...dont let the CNC do all the work. If your shape involves hogging out half of the material than roughly trim off that material with a knife beforehand. May not necessarily save time, but it will save on the pink fluff.

[@AaronHendu]

Latex house paint can be used to "prime" the foam...flat cieling paint works great and goes with the drywall filler well. After the latex has curef, you can use some spray paints on top. I tested that rustoleum 2x and some rubberized auto undercoating on a scrap piece about 6 months ago and no bubbling or lifting has occured. I also tested several types of silicone caulk and adhesives which melt foam and the latex paint primer worked there as well.