Fiberglass - 178 pieces of wood later...

[Micro469]

Juneaudave ...... Don't Know if this is pertinant to your build, but maybe I can defer a small problem I ran into with my trim. Your trailer is so fantastic that I'd hate to see any blemishes show up as time goes on. About your trim...are you leaving the edges square or are you rounding them off? My trim has started to peel right at the edges, and it really hasn't been out that much. When I went camping at ADK, Steve F. saw it and muttered something about surface tension on the edges of the trim, and how the epoxy would pull away from the edges, so that however number of coats you give it, it would still be very thin. I now find moisture is getting under the edge, and causing the epoxy to lift. To fix it I am going to have to sand a roundover along the edges... won't be able to do it with a router, and the re-epoxy the trim again.... Probably the whole tear.

Just something to think about before you install the trim..

[Juneaudave]

Excllent point John!!! I've been thinking about that a lot, and need to put a little more thought into it. My outside trim is flush and the outside edge will be rounded over with a mega 1 1/2 roundover....but I've been feeling lazy about some of the inside edges...your comment is probably going to cause me another day of work!!! Details kill a guy!!!

[WarPony]

... When I went camping at ADK, Steve F. saw it and muttered something about surface tension on the edges of the trim, and how the epoxy would pull away from the edges, so that however number of coats you give it, it would still be very thin. I now find moisture is getting under the edge, and causing the epoxy to lift....Just something to think about before you install the trim..

Wow, I was under the impression that epoxy was the ONLY way to go because of the durability it has. I had no idea sharp edges would cause a problem like you have.

John, what brand of epoxy did you use? I'm glad I ran into this thread before I bought any epoxy or 'glass product.

Jeff

[Dean in Eureka, CA]

Inside square corners are easy, just add a fillet of thickened epoxy.
Outside square corners... Yup, gotta round 'em over.

[Micro469]

... When I went camping at ADK, Steve F. saw it and muttered something about surface tension on the edges of the trim, and how the epoxy would pull away from the edges, so that however number of coats you give it, it would still be very thin. I now find moisture is getting under the edge, and causing the epoxy to lift....Just something to think about before you install the trim..

Wow, I was under the impression that epoxy was the ONLY way to go because of the durability it has. I had no idea sharp edges would cause a problem like you have.

John, what brand of epoxy did you use? I'm glad I ran into this thread before I bought any epoxy or 'glass product.

Jeff

I used the West System epoxy....supposed to be one of the best...I guess it depends on how it's applied....

[tonyj]

You should also consider the fact that epoxy has nothing in the area of UV inhibitors and will break down over time with sun exposure. The only way to prevent this is to cover it with varnish that has UV protection (like schooner varnish) or possibly automotive clearcoat. I am sure about the varnish, less sure about the auto clearcoat.

[Micro469]

You should also consider the fact that epoxy has nothing in the area of UV inhibitors and will break down over time with sun exposure. The only way to prevent this is to cover it with varnish that has UV protection (like schooner varnish) or possibly automotive clearcoat. I am sure about the varnish, less sure about the auto clearcoat.

I know that, but I think my problem has more to do with moisture penetrating underneath the epoxy than the epoxy breaking down. When the epoxy starts to break down it goes cloudy.....Maybe if I had coated it sooner with varnish it wouldn't have happened so quickly, but it still would have happened. The varnish would still have had the surface tension problem at the square edge, and would be more difficult to fix once varnished. Now, I just have to fix the edges and then re-epoxy.... when its right I can varnish.....or clearcoat.

[WarPony]

UNHIJACK!!!!

Dave, that hatch looks great...... hell, the whole build is a work of art!!!!! Thanks for posting the pictures, it's been a great inspiration for me to build woodies.

Jeff

[Juneaudave]

UNHIJACK!!!!

Dave, that hatch looks great...... hell, the whole build is a work of art!!!!! Thanks for posting the pictures, it's been a great inspiration for me to build woodies.

Jeff

Thanks Jeff, I sure hope I'm helping...It's not the epoxy that John used...it's the fact that it's really, really difficult to have a sharp edge. The epoxy wants to pull away...and you do a little sanding...and all of a sudden you have this sharp edge that moisture can get into. Your much better off rounding it over...even if it is just a little bit. I use a 1/8 inch roundover from MLCS to ease that edge just a smidge...that's about all it takes!!! I was thinking about skipping that step...but John's post reminded me not to take a shortcut at this point!!!

[del]

Dave that hatch is looking nice (beautiful, awesome, ext). Pat yourself on the back.

del

[angib]

When I went camping at ADK, Steve F. saw it and muttered something about surface tension on the edges of the trim, and how the epoxy would pull away from the edges, so that however number of coats you give it, it would still be very thin.

I would suggest (but I can't prove it) that at the edges, you've got exposed end grain. Epoxy is drawn up the end grain by capillary action and that can leave the surface short of epoxy - and incomplete epoxy means there will be voids that will attract moisture.

I was taught (by a boatbuilder who expected epoxy to last 20 years) that when applying epoxy, end grain should get two or even three applications from each mix of resin - first, you paint the end grain, then apply the epoxy elsewhere, then come back and apply more resin to the end grain again. You're trying to see just how much epoxy you can get to soak in - here, economy is the direct opposite of durability. Disposable brushes are a good idea too, as you want to keep applying the resin until it starts to gel, by which time your brush is a gonner.

This is tedious to do - but then ain't that always the way with quality! If trying to get a really nice smooth coat to be sanded and varnished, like Dave's wood-strip, there's a lot to be said for doing all the end grain first as a separate exercise and then doing all the 'flat' stuff second.

Contrary to some advice here (which I believe has to do with paint, not epoxy), I was also taught that under no circumstances, ever, should epoxy be thinned. The objective is to get a 100% layer of epoxy immediately below the surface - thinning will produce a deeper layer, but of porous epoxy as it will be full of voids where the thinners has evaporated.

Andrew

[doug hodder]

I've also found that you need to coat out the back of the pieces on your side "framing". Any area once it is applied that doesn't have a complete seal will allow water to get in and penetrate from the back side, which will eventually appear in the surface. Epoxy encapsulation like this is common practice on boat building. Plan on sealing up all the joints/ mating surfaces really well will no voids and sand off the hard 90 degree edge. It doesn't need a full roundover like from a router, but the hard edge like out of a planer won't work. Doug

[Micro469]

Just to show what I am experiencing, here are a couple of pics....










Not very clear, but you get the idea....

[Juneaudave]

John...I've never really seen anything like that except on boat gunnels where tie down straps or something rubs over time.

Is it possible that there is a compatibilty issue going on? It sort of looks to me like either there is a stain/epoxy issue like the epoxy didn't penetrate in...or maybe...did you wipe down with a solvent of some sort prior to applying epoxy? It can sure be fixed but it would be real nice to figure out whats up. I know for a fact that the MAS epoxy I use doesn't adhere well with the oils in the purple heart unless wipe down with acetone first...that's why I ask....Juneaudave

[Micro469]

John...I've never really seen anything like that except on boat gunnels where tie down straps or something rubs over time.

Is it possible that there is a compatibilty issue going on? It sort of looks to me like either there is a stain/epoxy issue like the epoxy didn't penetrate in...or maybe...did you wipe down with a solvent of some sort prior to applying epoxy? It can sure be fixed but it would be real nice to figure out whats up. I know for a fact that the MAS epoxy I use doesn't adhere well with the oils in the purple heart unless wipe down with acetone first...that's why I ask....Juneaudave

The wood is Poplar,unstained. Just sanded. Now that I think back, I did wipe the sawdust off with a Tack cloth prior to epoxy.....That wouldn't have done it would it? I find the epoxy did not seem to penetrate the Poplar.......