Waterbased PolyCrylic for glassing ???

[Kormier]

With winter just around the corner I soon won't be able to keep my garage door open when doing fibreglassing, which causes a problem since I hate putting projects on hold. I thought I would start experimenting with some other types of resins that produce less of a stink (and therefor more "wife-friendly"...).

Yesterday I made some test FB shells using Minwax polyurethane (had lots on hand since I use it to finish woodworking projects) and I also picked up a can of Minwax waterbased polycrylic since waterbased products usually don't smell as much. Both seem to work well when applying fibreglass mat to silicone but I'm curious to see how strong the final products will be compared to the Bondo brand fiberglass resin.

I'll keep you posted on my observations. Has anyone tried this before ? :confused

 

[robn1]

Never heard of that being used, it's a good clear coat though. Have you tried epoxy? It doesn't stink much at all and it's commonly used for fiberglass.
WEST SYSTEM | Epoxy Resins and Hardeners

 

[Sean]

I too will be running into this problem.so all info will be welcome...

 

[Kormier]

Well, none of my shells are fully cured yet and its been 24 hours... It's not looking too promising but we'll see how they look tomorrow.

 

[Kormier]

Never heard of that being used, it's a good clear coat though. Have you tried epoxy? It doesn't stink much at all and it's commonly used for fiberglass.
WEST SYSTEM | Epoxy Resins and Hardeners

Heard of it but never tried. I might try to get my hands on some epoxy resin if my little experiment doesn't give me the results I'm looking for.

 

[Kormier]

Never heard of that being used, it's a good clear coat though. Have you tried epoxy? It doesn't stink much at all and it's commonly used for fiberglass.
WEST SYSTEM | Epoxy Resins and Hardeners

Just found a local place that sells it and it's not cheap!

They sell the #206 slow cure kit 39 oz with hardener for $69.50 (Canadian Dollars). ...

Might be the price to pay to keep the wife happy... :wacko

 

[robn1]

Yeah it's pricey but highly recommended. I'm sue any brand of epoxy will do, just make sure it's thin and has enough working time. I've used a 30min hardware store epoxy with good results.

 

[exoray]

You need to use a chemically reactive cure lamintating resin to do fiberglass, not an air dry clear coat paint...

As said epoxy laminating resin is probably going to be your best bet... You also need to verify that that cloth and/or chopped strand you are using is epoxy friendly, many of them have 'binders' that melt away in polyester resin but don't in epoxy and that will cause the resin to not properly bind and soak into the fibered glass strands...

 

[PepMaster]

Whenever it get's closer to winter all I use is urathane casting resin. I'll mix up a small batch grab a chip brush and brush the outside as quick as I can. Then I'll mix up another batch and slush the inside of the pep piece with resin and when I'm done it's hard as a rock.

 

[robn1]

...You also need to verify that that cloth and/or chopped strand you are using is epoxy friendly...

I didn't know that, thanks.

 

[exoray]

I didn't know that, thanks.

When it doubt contact the supplier, if you are using Polyester or Vinyl Ester resins you have no worries as the solvents in them will dissolve the binders, but once you make the switch to Epoxy resin you need to verify that the cloth/mat is made with an epoxy friendly binder, not all are... In fact many legit suppliers will highlight the fact that their cloths/mats are epoxy friendly while other supplies will conveniently forget to disclose that info, or say simply 'for Polyester' never actually stating that it's specifically not for epoxy use...

 

[Sean]

what about this stuff.I have no idea if it would work.but it sounds as if it could be used indoors.
Aqua-Resin® | Overview

 

[exoray]

what about this stuff.I have no idea if it would work.but it sounds as if it could be used indoors.
Aqua-Resin® | Overview

Honestly that is a different league altogether, it's a plaster with a polymer binder...

What you get with that is a fiber reinforced plaster casting, not a true fiberglass laminate...

In fiberglass the strength comes from the fiberglass, the resin is simply a binder to hold the fiberglass in shape... In the aqua resin system, you have a binder and plaster that is the main component the fiberglass ads to the strength of the plaster/binder but it no the core of the strength...

It some cases one or the other might work better but it's far from a universal substitute for fiberglass...

 

[Kormier]

Yeah it's pricey but highly recommended. I'm sue any brand of epoxy will do, just make sure it's thin and has enough working time. I've used a 30min hardware store epoxy with good results.

I'll stop at Home Depot tomorrow and see if I can get my hands on some.
The other price I had found was from Lee Valley tools.

 

[Kormier]

You need to use a chemically reactive cure lamintating resin to do fiberglass, not an air dry clear coat paint...

As said epoxy laminating resin is probably going to be your best bet... You also need to verify that that cloth and/or chopped strand you are using is epoxy friendly, many of them have 'binders' that melt away in polyester resin but don't in epoxy and that will cause the resin to not properly bind and soak into the fibered glass strands...

I did not know this as well, thanks !

I think that my little experiment can rule out Polycrylic and polyurethane as a good option for glassing... what a mess... Both shells are very brittle so no good for silicone mold support.

 

[exoray]

I'll stop at Home Depot tomorrow and see if I can get my hands on some.
The other price I had found was from Lee Valley tools.

About the only cost effective epoxy you will find at the big box hardware stores is the stuff they use for pour coating counter tops... Check the paint department...

It will work OK but it's best to get real laminating resin if you plan to continue doing stuff as it's designed for the purpose...

 

[Kormier]

Well... my test confirms that polyurethane and polycrylic does not work for glassing. Even after an additional day of curing the results are not better. My two test shells will be picked up with the garbage tomorrow.
I guess there's nothing better than the real thing after all. :wacko