How to make an Acoustic Guitar Mold | Building an Acoustic Guitar

[@KennethRayable]

I never saw a mold being built before. I’m impressed. You are a true craftsman.

[@homebuiltshop]

Thank you! I appreciate that. This mold was actually pretty neat to put together and it should last me a long time.

[@watchnlearn2731]

Floating block is a great idea. In fact it’s the best way

[@homebuiltshop]

It seems to me that it won't be so hard to align when clamping in the sides. I'll find out before long.

[@TheArchitect097]

Looks awesome to me, and the spreader idea was awesome. gonna come back to this when I make my own mold.

[@homebuiltshop]

Thanks, I'm glad its helpful for you.

[@VedunianCraft]

You're a life saver!! Love your video, perfectly explained!!

[@homebuiltshop]

Thanks! I'm happy it was helpful.

[@SkyscraperGuitars]

You're one step ahead of me!!! Just wrapped up my frame today... Spreaders are next.

[@homebuiltshop]

Awesome! They say great minds think alike. Lol.

[@crazyrees23]

Did you cut to the inside of the line for frame mold and outside of the line for side bender pieces?

[@maurikmalasllani2848]

You are a true master mate. This is a very helpful video as i’m trying to build an acoustic guitar myself. Thank you and compliments.

[@homebuiltshop]

Thank you. Good luck on your guitar. Its going to be awesome I'm sure.

[@maurikmalasllani2848]

@@homebuiltshop Thanks a lot mate.

[@punkeyes8401]

man I've been watching and learning from your channel since you started it! Truly inspirational dude thanks for passing on the knowledge

[@homebuiltshop]

Thank you for your continued support. I really appreciate it.

[@monkeypuzzler]

Love your videos mate. You have a great way of describing your processes. Thanks for posting them

[@MadAsKiwi]

Cool idea with the floating blocks. If I was to build an acoustic guitar, that would be what I would do. However, I would have cut the hole for the turnbuckles out of the middle piece of MDF then drilling the outer ones before gluing together to save time later, but that's just me. Yours looks like they will do the job perfectly!!

[@homebuiltshop]

Thanks. That seems to be a popular option. It would be super easy to do as well.

[@jimcrines1994]

Nice Video! You might want to consider making the blocks small enough yo remove thru the sound hope. That way you can leave them in during the entire glue up of the body. Also the finish of the block , inside the form, should include the thickness of the sides as that will slightly change your radius.

[@homebuiltshop]

Good idea! I can easily adjust the size and radius when I get to that point if I need to.

[@chillertechtexas4375]

Gunk.... definitely a technical term!

[@markmelville6670]

I just finished one of these. I only used one set of spreaders though and placed them at the waist(narrow part) of the mold. I used 5/8" oak dowels through the spreader hardware. There should not need to be that much pressure on the sides. I used leather too.

[@crazyrees23]

Did you cut to the inside of line for frame mold and the outside of the line for the side bender pieces ?

[@Kkuts37]

Awesome! Looking forward to more!

[@homebuiltshop]

Thanks! There's plenty of more to come.

[@miguelangelstratocaster5159]

Gracias muchas gracias por tus fabulosos videos. Esta tarde te he descubierto aquí y llevo ya unas horas viendo todo el proceso de construcción de esa guitarra acústica. A pesar de no hablar tu idioma me resultan muy comprensible! Podrías por favor hacerme una lista con las herramientas mecánicas (regruesadora, lijadora, cortes de cinta, etc) que has utilizado y sus costes? quiero montar mi propio taller amateur para mis propias guitarras ==== Thank you very much for your fabulous videos. This afternoon I discovered you here and I've been watching the entire construction process of that acoustic guitar for a few hours now. Despite not speaking your language, they are very understandable to me! Could you please make me a list with the mechanical tools (thicknesser, sander, tape cutters, etc) that you have used and their costs? I want to set up my own amateur workshop for my own guitars Thank you man

[@TempleGuitars]

Another fantastic and informative episode.

[@homebuiltshop]

Thanks Brother! This whole process is going to be a fun learning experience for me. I'm looking forward to it. Have you done an acoustic before?

[@eddioritz2580]

Absolutely awesome and inspiring, thank you thank you !!!!!

[@2AChef-n-BBQ]

This is a fantastic informative video, great job Jeff👊🏼🥃🇺🇸

[@homebuiltshop]

Thanks man. I appreciate it.

[@frr1107]

Great video, I‘ll adapt this concept to build a 335😁 I would guess the floating block should work great

[@homebuiltshop]

I think so too, but we'll see how it goes.

[@c.p.1589]

Really nice job. I'm thinking that the spreader blocks should not be an exact fit with the mold inside curves. There will be approx 3 mill of side wood between those surfaces, meaning they won't fit cleanly and there'll be uneven contact and high spots. Adding the leather padding will increase the error. It might be fine, I don't know( I'm about to start my first build too). Rather than cut the mdf on the bandsaw, then flush trim it with the template and router, is there some way to use a very narrow router bit to cut the the waste out and then use the waste to make the blocks? The router kerf and adding a layer of leather might leave a gap that matches the average side thickness. Hope that makes sense.

[@danawheeler6517]

You can make the spreader slot without the bolt. It works just fine and might be easier to remove Also you can also create the slot by cutting it into the middle piece before the glue up.

[@homebuiltshop]

I considered cutting the center piece like you mentioned. I'll see how this works. I can easily remove the bolt if I need to.

[@watchnlearn2731]

Excellent video

[@homebuiltshop]

Thanks Brother!

[@roberthatten]

Awesome video!

[@MDLuthier]

Over 20 years both acoustic build and repair work... believe me - those spreaders really need to fit through the sound hole if shape is to be maintained through the plates going on the rim. For those that are not getting accurate or stable bends on their sides, you really want to work on tweaking your process. - either pipe or blanket bender - to get close enough that a single waist spreader gets the side in close contact along the entire mold. For those that have some issues there, a small upper and lower bout spreader will usually pull things back into alignment, but try to go into the profiling, side tape, and lining process with as accurate a set of sides as possible. On MDF - heavy, not very stiff, and will need some protection from water. 18mm Hardwood plywood - even the poplar-core stuff from Home Depot - is nicer to work with and about 75% of the weight of MDF, and only about $20 more a sheet (a mold with spreaders and . To get the same stiffness in the mold through the waist, MDF needs to be 3" wide, versus about 2-3/8" for plywood, as stiffness is about 50 percent of hardwood ply in-plane . Again, MDF is about 65 lb/cu ft versus about 38-40 lbs/cu ft for hardwood ply, so plywood molds weigh about half of what an MDF mold will weigh for the same stiffness (which is why you want a mold to begin with). You want to be able to easily hang the mold off a luthier's swivel-jaw reaper vise for linings, etc, so weight matters. You also want to be able to hand a mold which is in use off the floor and out of harm's way until the closed box is ready to come ou too the mold. A 5/8" hanger hole centered about 1-1/4" up from the inside edge of the upper bout profile and on the seam between halves of the mold keeps things out of the way of the carriage bolt/wing nut closure, and a modified screw-in ladder hanger bracket (heat the bent-up tip and bend such that there is just enough upward kick to keep the mold on the hander). Titebond is a good utility glue for this work - horrible for actual instrument construction (it hot and cold creeps, is challenging to regale without full removal, and has such poor initial tack that you'll have to either use alignment pins or clamp twice - ounce to get most of the excess glue squeezed out, and then again for alignment).

[@kevinrappold7795]

What type of bandsaw blade did you use to cut your acrylic? Do you know the TPI? And size?

[@mrfatbobrider1969]

Hi brother That middle piece of MDF for the turnbuckle would have been good to trace the loop of the turnbuckle on to it then cut he shape out then fit together. Just a thought, if it makes sense 🤔

[@homebuiltshop]

You mean before I glued it up? I thought about that but decided to try this instead.

[@mrfatbobrider1969]

@@homebuiltshop yea before glue up , but then I guess the way its done now you can dismantle it if you have to 👍

[@thebigswede1736]

I would have thought you'd have to allow for the sides thickness especially with leather attached. Thoughts?

[@homebuiltshop]

Thats a possibility. If I need to adjust it when I start working on the sides, it shouldn't be too hard. I'll see how it goes.

[@stevesstrings5243]

Great information! Thanks!

[@dalgguitars]

Any thoughts about copying plans? Most plans have a "do not copy" line on them. I'm just starting my first acoustic build and am wrestling with this idea. I think the "do not copy" is about copying and selling the plans. And since we are not selling the plans, just using them, I think it is within our rights. But I just would like to hear your take, if you would be so bold to tell us.

[@homebuiltshop]

I personally had copies made of my plans. I have zero intentions of selling them. I think its OK to copy them for your own use. I went through several copies as I cut them up to make templates. I can understand why they don't want you to make copies but I don't know any other way around it when you only get 1 copy when buying the plans.

[@marccabardo864]

It's cool. But I have a question. Is your spreader block gonna come out in the sound hole? Cause It looks to big to me. I'm just curious.

[@homebuiltshop]

Good eye. My Spreaders will not fit through the sound hole. I don't plan to close the box with the spreaders still in place. I'll remove them before adding the top.

[@marccabardo864]

@@homebuiltshop ah I see. Nicely done sir.

[@thefreese1]

I think the floating turn buckle is a perfect idea..it will aloow it to self adjust up and down and side to side.. and will make it so the wood fits the mold perfectly.. Just one suggestion.... as far as glue goes .... for your instrument , use the original Tite Bond . Not 2 or 3.. youll thank yourself later on if you need to do a repair or a neck reset.. Titebond original is a standard nowadays with luthiers and factories for this same reason.... and stay away from hide glue ... fish glue is handy in non critical spots .. but you can usually use tite bond there too ..

[@MDLuthier]

I view Titebond as a nice beginner's view, but is a pain in the butt to repair. 192g hide is standard for a lot of custom builders and 315g for bridges is becoming more common as the strengthened faster drying time becomes known.

[@thefreese1]

@@MDLuthier yes, it is the standard for a whole lot of luthiers. Because of tradition and they believe it's the best stuff out there. But the stuff is made from animal hide and is inconsistent.. one batch will glue it so hard you can't get it apart no matter how much heat or steam you use.. the next batch may fall apart in a few years... I heard a good luthier once say " stradivari was a perfectionist and he used the best tools available of the day. Because that's all they had ...And if he was alive today he would look at all those luthiers and say why in the heck are you still using hide glue ?" Original Titbond, LMI (now stewmac) have been the go to glue for many fine luthiers.. You know, back in the day they used to pour babit bearing for main bearings for crank shafts or use leather as a connecting rod bearing...and cast engine blocks with pig iron ... 😁

[@thefreese1]

@@MDLuthier BTW , I've never had a problem separating a glue joint with Titebond.. I have with Hide glue.. in fact I'm working on one now that I'm going to have to use a more invasive approach to repair.... the proteins vary from hide to hide when making each batch..and this one must of came from a mule....

[@MDLuthier]

Titebond creeps cold and hot, leading to numerous issues with failed/slipping bridges and other loaded structures, failing glued neck joints (eg, Martin's M&T), and much more complicated reglue due to dried Titebond acting to contaminate the joint. I understand the attractive nature of Titebond - it's easy for new builders to handle, does not require any new skills to be developed, and. - in properly made joints - should not show a sensible difference acoustically. But after 20 years of doing build and repair work, hide is significantly easier to both build and repair with IF you can push through the first couple days of getting handling down and order of operations. @@thefreese1

[@MDLuthier]

Not so much tradition or indeed ignorance, but rather the enduring truth of the adage, "You don't know what you don't know until you know it." 20 years of hands-on with the stuff helps reveal strengths and weaknesses as well. I'm also an aerospace engineer, aircraft builder, and think tank technology futurist, so if there was a better adhesive for guitar building and general instrument construction, I would jump on it. But after the first 50 or so instruments built and what was hundreds of structural repairs, I settled on hot hide and fish, plus CA and a bit of epoxy for nearly everything on the build/repair side, with Titebond used for jigs and fixtures plus the rare 'safety fuse' joint which I want o see fail to save something else. FWIW, I don't believe an adhesive is truly reversible unless I can use the same solvent to remove it as I did to make it. Titebond and epoxy are thermoplastics, so full removal takes time and additional solvents or mechanical removal... that time spent cost the customer money, so planning ahead for repairs (neck removal; wet-set refrets, etc.). I am in agreement with you that it is not an acoustics thing, as glue lines should be well under 0.001" under clamps... just not enough glue to really matter.@@thefreese1

[@cpwhiskey]

Any reason you didnt glue the layers first and then cut it out? To me it would seem it would save time rather than making 6 copies

[@reesriddoch5332]

does the piece at you cut off at 5:59 become the piece for your bending jig? Could you use that internal cut piece for the bending jig? What size of dowel did you use?

[@crazyrees23]

So would it make sense to cut the outside of the line for the side bending pieces?

[@scottmorris4914]

Any idea of where to get these plans?

[@homebuiltshop]

LMI sells the plans you can use to make all the templates.

[@barrymesser1732]

Send more videos on how to make molds for hollow-body guitars and not guitars also

[@neilforehand1121]

Why wouldn’t you just take the paper cutout and transfer that to the MDF? Use the first one as your master and make the other 5 off the MDF master. I’m sure there is a reason, just not sure if I understand the reason.

[@homebuiltshop]

Thats definitely an option. I decided to try it this way so I can keep the separate master. This way I can easily make more in the future if I need to for some reason. Going straight to the MDF would work just the same.

[@neilforehand1121]

Thanks for the reply! Love your videos and look forward to the acoustic build!