# automotive fiberglass resin ok?



## maniac (Dec 27, 2010)

Has anyone ever tried to use automotive fiberglass resin for a poured on wood finish? i'd like to a very thick builtup finish for a bar top. Seems like it would be about a third the cost of other poured on epoxy finishes. I'm talki g about the two-part resin for doing automotive bodywork. from my experience it shoul polish up well, but will it adhere to a wood surface? Any thoughts or experience?

Ken


----------



## gstanfield (Dec 23, 2011)

As a boatbuilder I can answer this one with tons of experience.

In short, a polyester resin will have a poor bond to wood. There are many variables including prep, mixture, etc and it will bond decent, but I've also seen it peel off in huge chucks. Epoxy resin is vastly superior in terms of strength, bond, lifespan, etc. I use a lot of system three and marinepoxy form http://boatbuildercentral.com/ but another good source for epoxy (including thick "bar top" stuff) is http://www.aeromarineproducts.com/ 

If you are planning to go super thick I would go with the thick stuff made for table tops and bar tops, but if you are going to be happy with 1/8-3/16 thick then I'd go with a thinner epoxy and put several layers on "wet on wet" where you wait until one coat is still a little "tacky" or almost dry and then put another coat on until you are at your desired thickness.

I know you're not building a boat, but here is an example of polyester on wood and how poor the bond can be if everything does not go PERFECT! I have seen this happen many times! The polyester/fiberglass layer just peeled right off after just a few years of use!


----------



## maniac (Dec 27, 2010)

Thanks George. You probably just saved me a lot of re-do time.

Ken


----------



## gstanfield (Dec 23, 2011)

No problem! I've been through the trial and error and learned that saving money can get very expensive  Do it right and do it once. 

Hope your project turns out great!


----------



## ponch37300 (Feb 27, 2008)

While I have no experience with bar top epoxy or how plain fiberglass resin would look on one I have done a lot of custom work with wood/fiberglass projects for car stereos a few years back. If done correctly(nothing to special) fiberglass to wood bonds can be very strong. Now, I've never just poured resin on wood, I always used fibergalss matt and the resin bonded the matt very well to the wood. And these bonds took a major beating, cosntent vibration from the speakers, some over 160 decibles which would basically be like taking a baseball bat to your bar top. So while I can't comment on how well it will look or if just the resin would give a good bond I can say that fiberglass matt can be bonded to wood very well with fiberglass resin so I would THINK that the resin would be able to bond by itself. But not sure how it would look since most glass resin has a tint to it that may not give the look you are after.


----------



## bartbarry (Jan 18, 2012)

From my experience...Like ponch said, adding mat or even chop to the equation will produce a strong bond (wood must be VERY DRY) Moister will kill the bond. The drawback as far as asthetics goes, is that the mat will obscure the wood grain. It will not show the natural beauty of the wood at all. If you want a show piece featuring the natural beauty of the wood, then opt for the high performance resins as George suggested. Beauty has a price


----------



## Vikki (9 mo ago)

gstanfield said:


> As a boatbuilder I can answer this one with tons of experience.
> 
> In short, a polyester resin will have a poor bond to wood. There are many variables including prep, mixture, etc and it will bond decent, but I've also seen it peel off in huge chucks. Epoxy resin is vastly superior in terms of strength, bond, lifespan, etc. I use a lot of system three and marinepoxy form Home - Boat Builder Central but another good source for epoxy (including thick "bar top" stuff) is Epoxy Resin | Polymer Supplier | AeroMarine Products
> 
> ...


Can I use fiberglass resin instead of polyurethane on wood I just stained? I want that glossy look. We have knitted pine planks on our walls and I just stained some and was wondering.


----------



## Steve Neul (Sep 2, 2011)

maniac said:


> Has anyone ever tried to use automotive fiberglass resin for a poured on wood finish? i'd like to a very thick builtup finish for a bar top. Seems like it would be about a third the cost of other poured on epoxy finishes. I'm talki g about the two-part resin for doing automotive bodywork. from my experience it shoul polish up well, but will it adhere to a wood surface? Any thoughts or experience?
> 
> Ken


It doesn't pour or flow out very good. Even if you help it with a brush it ends up all lumpy. It also has a very amber color to it. When I did it I planned to paint over it so the appearance wasn't that important.


----------



## Biotec (Mar 14, 2021)

Been down a similar Avenue with polyester resin and epoxy resins and their problems.

sailing small and large sailboats pretty much forces you to learn how to do your own repairs.

unfortunately those mistakes may have been expensive but nowhere at the cost of it is now. some of the resins have almost double in cost in last three years. I would suggest looking at the videos Blacktail productions as he talks about his Great accomplishments and some near misses.
How Strong is an Epoxy Table?

he has several video's on resins


----------



## Kudzu (Dec 23, 2008)

My FIL used to tell the story of his neighbor spending a ton of effort to 'glass' a older wood skiff he had. He finally got it done, was extremely proud of it and took it out for the maiden voyage.....

The glass peeled off going down the lake and was floating on the surface of the lake.


----------



## dbhost (Jan 28, 2008)

gstanfield said:


> As a boatbuilder I can answer this one with tons of experience.
> 
> In short, a polyester resin will have a poor bond to wood. There are many variables including prep, mixture, etc and it will bond decent, but I've also seen it peel off in huge chucks. Epoxy resin is vastly superior in terms of strength, bond, lifespan, etc. I use a lot of system three and marinepoxy form Home - Boat Builder Central but another good source for epoxy (including thick "bar top" stuff) is Epoxy Resin | Polymer Supplier | AeroMarine Products
> 
> ...


Thanks for posting this. I am in the planning stages of a Foamie camper that will include wood framing and I am considering fiberglassing it instead of using PMF, looks like other than the polyester resin eating XPS foam for lunch, not sticking well to the wood is another reason not to use it...


----------



## gstanfield (Dec 23, 2011)

Vikki said:


> Can I use fiberglass resin instead of polyurethane on wood I just stained? I want that glossy look. We have knitted pine planks on our walls and I just stained some and was wondering.


You could depending on the stain, but I don’t like using resin as a topcoat, even epoxy. The resin isn’t UV stable and will break down over time from exposure to UV light. Some epoxies have UV inhibitors in them, but they still aren’t as good as an actual topcoat. For my boats I topcoat the epoxy with automotive clear coat and it lasts incredible.


----------



## _Ogre (Feb 1, 2013)

10 year old thread people, vikki should have started a new thread

we use fiberglass resin for car stereo speaker builds, consoles and door panels
the bond between resin and wood is quite substantial, there is no physical way to separate them
there's a big difference between dry indoor wood and wet boat building

when fiberglassing over wood i brush on an initial coat of resin, it soaks in deep like a stain
sub-woofer speaker rings and enclosures are pretty brutal to wood/mdf and fiberglass
typically i route a groove to staple fabric into and paint it with resin and let it kick off
i then top coat with multiple layers of fiberglass mat to a desired stiffness depending on the use
this sub enclosure has 8-10 layers of .5oz mat to keep flex out of the enclosure, 1/4"+

i finished my 58 truk build 12 years ago, there has been no failure of wood/resin joint anywhere in the truk
there's a 600 watt amp powering just the single sub woofer. if anything would have failed it'd be this

this is a kick speaker ring, it shows the edge detail for stapling in fabric










subwoofer speaker ring temp held in place










fabric stapled on sub enclosure. tape and wax used to keep critical surfaces clean










lots of steps later...


----------



## allpurpose (Mar 24, 2016)

Fiberglass matting paints well, but I'd fill in the low spots and flaky areas with bondo and sand the living crap out of it.
Just a reminder..If you're using bondo add as little hardener as possible as long as it'll still set up and cure. The less hardener the stronger the bondo will cure. (LOTS of sanding however.) The more hardener the softer it'll cure and it'll likely leave small bubbles in it..Sounds counter intuitive , but that's how it works..


----------

