How to paint foam - waterproofing foam board - make your foam projects hold up!

[@tull807]

Good Info, thanks. Watching Flite Test building videos, they covered all outside edges with hot glue and used an extra piece of foam board to smooth it down. This might help the outer edges be more water resistant and help glue the paper down. Hope this info helps.

[@magicalframe9441]

cutting a foamboard-width slot in a piece of foam, laying down a thin glue bead over the edges of your model, then using the tool to squeegee the glue down into the seam works well to waterproof the edges

[@lysadoan9731]

So are you supposed to apply the paint before the polyurethane or after? Some people apply paint before but im not sure

[@DoItYourselfDad]

I've done it both ways, whichever way to you do it, just don't saturate the foam with paint, light coats is the trick.

[@Jazzman-bj9fq]

With the MinWax, although I've heard that it's effective at waterproofing, I believe you have to scuff it up to get your paint to adhere better.

[@trevornelson7524]

im not sure if he painted after minwax or before. would seem to work better to protect the surface after its finished.

[@philipburton9518]

Is it not possible to treat the piece it is painted? Would a matte finish of Minwax, for example, over paint be a better solution to seal the whole thing - including the edges where moisture is bound to get in? To treat the foamboard and then paint over seems to compromise the effect. The paper surface is the best surface for the decoration, and it seems a way to seal the whole thing would be preferable. Does this make sense, or am I missing something? Many thanks.

[@DoItYourselfDad]

Yes, you can definitly paint and them coat it, you would just want to make sure the paint your using wont bleep when the minwax is applied

[@philipburton9518]

Thanks so much. I built an adobe arch over a booth at Santa Fe Indian Market - 10 feet wide; 11 feet tall - from cardboard and foamboard, and it was successful, but I was constantly afraid that rain would ruin all that work. I devised an elaborate cover of plastic sheeting, but I think coating it with water guard would be wise as well. Thank you so much. @@DoItYourselfDad

[@joang.4430]

With the spray varnish test, did you check to see if the layers also could separate as they did in the other versions: paint only, minwax and paint, and camp dry and paint?

[@najmakhan9572]

Im making something out of foam ..once ive finished how do i harden the foam so it doesnt break?

[@daviddewitt9365]

I am interested in painting the strofoam itself not the paper covering ... what can you do with that?

[@DoItYourselfDad]

Its going to be difficult becuase most spray paints will disolve the foam. Latex and acrylic paints work well though.

[@daviddewitt9365]

@@DoItYourselfDad Thanks so much ... I have discoverd that disovled coffee crystals will soak into the foam and give it a stained looking color, too!

[@pkeaton1]

I put a bead of hot glue along the edge of the foam then smear it in with a piece of scrap board. Then paint.

[@flyingcatfish]

How did the varnish hold paint?

[@jasonhurdlow6607]

The issue this testing doesn't address is that direct application of paint, unless done in very, very light coats will warp the foam core. Which is why the polyurethane is used, as it prevents this from happening when you paint. Also, it's not clear from this whether you wiped the poly off after applying.

[@benking4367]

Thanks man , gives me good ideas on my RC stuff

[@michellecreative701]

Can you give me advice on how to harden them? I use the for propos and sometimes they get dammaged

[@DoItYourselfDad]

Are you looking to ways to garden the foam? Of the paper covering on the foam?

[@michellecreative701]

Yes I am making large foam letters using styrofoam and foam board and I want to harden them

[@michellecreative701]

Harden

[@AzMovieMom]

I find that when I paint larger pcs of foam board, they warp...looking for a solution, so this test, with the tiny pcs didn't help me much but very interesting to see the minwax cause the paint to come off easier. Fun experiment, thanks!

[@olgoz1]

Did you ever find a solution to avoid warping on painted foamboard ? I've been searching for ages . . I use coloured packaging tape on my models.

[@AzMovieMom]

@@olgoz1 No, I didn’t. Sorry.

[@carlafox3957]

Why don’t you use flexseal to paint the edges so the water won’t get in before you spray paint

[@DoItYourselfDad]

Flexseal dissolves foam

[@Jazzman-bj9fq]

Hey DIYDad, nice vid. I have a question for you... I just ordered a foamboard model kit from Flitetest, of course I know you're aware of them, and I will be most likely paint it. Your vid is informative so now I know that I can paint the foam board directly. I would guess that you don't want to go on too thickly so you not only avoid runs but also you don't overly saturate the paper component with moisture, but you can still have problems with the paint flaking off or being scratched off. I wondered if you have heard of fixative? It comes in a spray can and you get it from art supply stores. It's used for pencil or charcoal drawings to 'set' the medium, no smudging or smearing of the graphite or charcoal. You're able to handle or display the artwork no problem. That might be a great solution to give something like a 'clearcoat' that would protect paint the same as a car's paint. From what I've read on it, Grumbacher's final fixative is acrylic based. Acrylic is supposed to be water insoluble once fully set which it looks like you showed in your vid.

[@DoItYourselfDad]

I love flite test stuff! My garage is full of FT projects. I've built a couple from kits and more from scratch. The foam-board that your kit will come with is already waterproofed.... I've scuffed mine up with a scotch bright pad before spraying which helps adhesion to their water resistant foam-board. I've heard of the fixative but haven't tried it before. If you give it a shot let me know how it works out. Happy flying!

[@Jazzman-bj9fq]

Yeah, I think my garage will be the same, lol. I really wish I had known about FT build kits a long time ago, I think that concept is great. I was watching your video because I live in SoCal and although it doesn't get humid here that often, in the rainy season it does get pretty damp. Yeah for sure, if I wind up using that I'll let you know how it works out. Happy flying for you too!

[@deadjester404]

Maybe try this with Walmart Ross foam board? The paper is better adhered to the foam inside

[@ShirleyLeeCouch]

Once you remove the paper, isn't it, then, waterproof?

[@DoItYourselfDad]

Most paint won’t stick to foam, also with a lot of the construction techniques the paper is used to bolster the strength of the model, but yes, if the paper isn’t needed by all means remove it and then you don’t have to deal with waterproofing.

[@RogueDragonNate]

ay FT arrow. I built one yesterday

[@DoItYourselfDad]

Love that plane, flys really well! Have fun!

[@freemansfocus]

Thanks for the info!

[@DoItYourselfDad]

Thanks for watching!

[@BlackScorpionx]

So you spray four white pieces and show the results with four red ones? Am i missing something here?

[@DoItYourselfDad]

Watch from about 2:50 on. I tested pieces treated in camp dry, minwax and varathane. Then I also tested those coatings with a coat of paint to test paid adhesion as well. In total 6 pieces were tested.

[@improvementTime10.3.17]

5:53 minwax one didnt work so well 6:20 spray paint winner

[@dchambers986]

I was super excited to see your video until I saw what you chose to test. May I humbly recommend MASONRY PAINT, RED GUARD, 100% Latex EXTERIOR paint, EXTERIOR ENAMEL, and/or just any kind of ROOFING paint/goop/substance. That's off the top of my head, but lacquer? that's not even recommended for this type of application (check out KCMA specs). MAYBE a CV or Epoxy resin, be whatever I used, I'd look for exterior so it's UV stable.