Beginner needing advice for painting fiberglass and plastic.

SPOautos

New Member
New here! Looks like a ton of info on this forum! Glad I found it as I do a lot of small projects like a body panel here and there, etc.

So my daughter is needing me to help her artistically paint a cooler (ice chest) and brand it. The cooler is plastic that has some flexibility, especially if someone was to sit on the lid. In addition to plastic, where the brand name is molded into the lid I was thinking I'd fiberglass it to fill it in using West Systems G/Flex epoxy fiberglass....used for Kayak repairs and such, bonds to plastic.

This is on a serious budget so like spray paint stuff since I'm not set up well for paint gun work and I don't need Quarts or gallons.

The process I have in mind.
1. D/A 180 grit to remove the coolers texture. Use 40 grit in the area I'm going to glass
2. Glass the top then sand smooth with 180.
3. Spray entire cooler with SEM flexible primer and surfacer.
4. Sand primer with 600 and guide coat to remove primer texture.
5. Have daughter do artwork using a combination of Krylon spray paint and going over that with enamel or acrylic artistic paints using brushes. (Not sure if she can do artwork on 600 grit so I'm thinking spray the whole thing with a solid color that can fill 600grit, then do the artwork on that.
6. Clear coat the whole thing with SprayMax 2K then wet sand and buff....I wish it was flexible but don't think it is.

Does that process seem okay? I initially was thinking the SEM flexible primer because being plastic I don't want someone to sit on the lid or something and everything crack. BUT, I'm not sure if the primer will be okay to go over the epoxy glass. Also not sure if the plastic really flexes enough to warrant flexible primer and paints.

I'm also not sure what is the best artistic paints for her to use.

It's important that it is durable because it'll get used, pulled out of truck beds, probably set stuff on it, etc....so want it to be as durable as possible using spray can items and such. Trying to keep it around $100 in materials.

Thoughts? Ideas?

Thanks for any info you can provide! Greatly appreciated!
 

Jim C

Oldtimer
well the only thing questionable here is the glassing of the name and plastic the cooler is made out of. most i believe are either pp or hdpe which epoxy by itself really wont stick to. also how deep is the area you are filling? if the fill is too thick and the lid flexes then the bond probably wont be strong enough and the filled section could pop out. if i was doing this, assuming the fill isnt too thick then i would scuff the lid, flame treat the whole lid, spray adhesion promoter then some epoxy primer. let that cure out and do all your work on that. if you dont flame treat and use adhesion promoter then nothing is going to stick with any kind of durability. if the filled area is 1/8" or less, evercoat makes a flexible filler for plastic called polyflex. havent used it in years but it may be a better choice as it will be a closer match in rigidity to the plastic on the lid VS fiberglass.
 

SPOautos

New Member
well the only thing questionable here is the glassing of the name and plastic the cooler is made out of. most i believe are either pp or hdpe which epoxy by itself really wont stick to. also how deep is the area you are filling? if the fill is too thick and the lid flexes then the bond probably wont be strong enough and the filled section could pop out. if i was doing this, assuming the fill isnt too thick then i would scuff the lid, flame treat the whole lid, spray adhesion promoter then some epoxy primer. let that cure out and do all your work on that. if you dont flame treat and use adhesion promoter then nothing is going to stick with any kind of durability. if the filled area is 1/8" or less, evercoat makes a flexible filler for plastic called polyflex. havent used it in years but it may be a better choice as it will be a closer match in rigidity to the plastic on the lid VS fiberglass.

I was also unsure about the glassing, I wasn't going to go that route until I found the G/flex they use on Kayaks and such, it's supposed to be able to flex. But I have zero experience with it and was worried it wouldn't work.

I looked at Polyflex and SEM Bumper Bite BUT dang they are $$$. Polyflex the smallest I've found is 30oz for $72-$90 and Bumper Bite is better but still $55. I need such a small amount I really didn't want to spend so much just to use a tiny amount.

USC has a "Flexible Glaze" I can get in a small 10oz pouch for about $20....but I thought a glaze had to be much more shallow like for pinholes or maybe chips. I didn't think I could really fill with it.....but maybe in layers where I let it harden them apply more?

I really don't know how deep the lettering goes, I haven't seen it in person yet. I'll try to go check that out today.

Do you happen to know if that SprayMax 2k has any flexibility at all? I don't think the cooler will get overly flexed, but I'm sure it'll get pushed into things, get sat on, etc and experience some minor flexing.

Thank You for your advice! I'm going now to research flame treating lol.
 

SPOautos

New Member
To add more info, I emailed Coleman and they said the cooler is made out of high density polyethylene. So looks like you were spot on a out doing a flame treatment. I just watched a couple videos on it.

What do you guys think about filling with the USC flexible glaze? If I use a glaze, do you think I should do it before the primer or on top of the primer and then primer again over the top of it?
 
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Jim C

Oldtimer
wow that stuff got expensive. just shows how long ago it was that i bought it. i remember it being 25-30 bucks. the polyflex is considered a glaze as well. you can fill a little with it though. glaze is no different than filler so you can use it in the same thickness as any other filler, its just thinner and more runny so more difficult to build up. i have no experience with any of the products mentioned. i have used west system many times but not the one mentioned.
 

SPOautos

New Member
wow that stuff got expensive. just shows how long ago it was that i bought it. i remember it being 25-30 bucks. the polyflex is considered a glaze as well. you can fill a little with it though. glaze is no different than filler so you can use it in the same thickness as any other filler, its just thinner and more runny so more difficult to build up. i have no experience with any of the products mentioned. i have used west system many times but not the one mentioned.

Then I think I'll try the USC glaze instead of glassing it. Do you think I should sand the fill area with 40 then fill then prime.....or should I prime the whole cooler then fill on top of primer then prime back over top of the fill to blend it in with the original prime?

Is epoxy primer flexible or do you think I should I stick with the SEM flexible surfacer?
 

Jim C

Oldtimer
spi epoxy is very flexible but its not really a surfacing primer so it doesnt build up thick. you can sand out minor imperfections with it but your not filling the texture on a cooler. you will need adhesion promoter no matter what. epoxy will not stick to the cooler without it. you will need to scuff it, used adpro then give a coat of epoxy then fill it.
 

SPOautos

New Member
spi epoxy is very flexible but its not really a surfacing primer so it doesnt build up thick. you can sand out minor imperfections with it but your not filling the texture on a cooler. you will need adhesion promoter no matter what. epoxy will not stick to the cooler without it. you will need to scuff it, used adpro then give a coat of epoxy then fill it.

Update!....I got a chance to put my eyes on the cooler tonight. The one she ended up getting isnt flexible at all, I even sat on the lid and it didn't flex. It is HDPE but I don't really need to worry about everything being flexible.

That being the case can I use some standard SEM high build primer and whatever filler and adhesive promotor I can get local?

I'm thinking maybe I can sand it with 180, flame the logo area then spray adhesive promotor and fill it (read I need to work it within 20 minutes after flaming). Then flame the rest of it one side at a time then spray adhesive and spray high build primer. Then block it all smooth with 400 grit. I think at this point I'll spray a background color just using something like Krylon and she will do all her artwork with either acrylic or enamel craft type paints, then I'll clear it all with Spraymax 2k clear.

I'm thinking before I put down the 2k clear should I treat it with adhesive promotor again since the artwork will be cured and I don't really want to scuff it?

Using IPA and tac rag at the various points where it needs cleaning.

Should that work well?
 
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