To completely fiberglass or not to completely fiberglass

[Geron]

I worked an Emmaus Walk this weekend (DeColores!) and met a guy who had built himself a TTT sized "houseboat" (6ft wide 6ft high Length???) had a bow and stern and could be used as a land camper while on the trailer.

I mentioned that I was going to strip my joints with glass and epoxy and just epoxy the rest of my Tear (no fiberglass just CPES and paint.) He cautioned stating that he had "just stripped" some joints and they had cracked (he used West Epoxy and mat). He leaves his outside in the sun.

What is your experience? Have you had joints crack when only the joints are glassed and the rest is not? Does is help keep cracks from happening if you "glass" the whole trailer? Just wondering since I talked with this dude.

I'm leaning toward glassing the whole TD now.

Geron

[glassice]

If you glass the whole thing you wont have dis-similar material" no cracks i try to replace the wood with foam for the weight

[Micro469]

If you glass the whole thing you wont have dissemer Mattel no cracks i try to replace the wood with foam for the weight

Don't mean to be rude Glassice..... But what do you mean by "dissemer Mattel" Do you mean "dis-similar material"??

[doug hodder]

Geron...I've got a couple of boats that I've built using the tape on the transoms to the bottom and didn't glass over the rest of them, I did glass the sides of the hull however but none on the transom.....no problems..1 is now 7 years old...I did use a complete epoxy system however...not CPES and tape...That may be some of the difference...Others may disagree, but I believe that mat is used to build thickness, tape is for strength. Also the joint should be well glued prior to glassing it...It's tough to make a call on what he experienced if you don't have an idea on the quality of product he turns out, it's entirely possible that he cut some corners that shouldn't have...just my opinion...doug

[Micro469]

Doug... CPES is basically a "watered down" epoxy is it not? If Geron was to strip and epoxy his seams with regular epoxy, and then use CPES over the rest of it it might work . I'd be more inclined to do the whole thing with regular epoxy.
My question is this.... If CPES has allready been painted on... will regular epoxy stick to it?

[madjack]

Geron, we built 2 skiffs when I was a kid...only the seams were glassed, the rest was painted in epoxy paint...these boats lasted well over 20 years with constant use and always either in the water or pulled up on the bank and rolled over...they laste with no problems until they were lost inaa big flood, back in "71...as far as I know, they are still in use by whoever found 'em after the flood
madjack

[doug hodder]

Micro....like I say...I know nothing about CPES and don't use it, but as I understand, it is a penetrating type sealant...It isn't made to build and be structural like an epoxy system...yeah...I'd do the whole thing in epoxy. I've used no cloth at all on the Rocketear and I have a 6" raised trolley top...just epoxy on the construction, (throughout) and top coat...I just don't think it is going to need the cloth on it as it won't be subjected to the water pressures, abrasion and sunken items like a boat hull will....and a good scuff sand would probably give the epoxy enough tooth for it to adhear...Doug

[Geron]

OK, Here we go.

... Use Epoxy filler in the screw holes
...Glass TAPE the seams, joints
...Seal with CPES -- I'll check with the rot doc but CPES marries well with epoxy according to my understanding. I believe it IS epoxy.
...Glass TAPE the seams, joints
...Paint with 1 part polyurethane Marine top coat

g

[angib]

I don't believe good epoxy can crack without the wood underneath cracking - epoxy has a high 'elongation to fracture' (that is, it stretches a lot before it cracks). You could get cracks along joints, but not if you stuck the joints together with epoxy.

But epoxy is open to mis-use - particularly from people who don't bother to measure out the components accurately or who apply it in conditions that aren't dry.

Andrew

[EZ]

Why do you want to use glass on the seams? Is it because you think they will break? Think about if it is really necessary. Using fiberglass tape will involve a lot of sanding to blend it in. I used that method in boat building but it might be overkill for a box. Or it might make for some nicely rounded strong corners. I just radiused (radiated?) the corners with a router and soaked epoxy into them as I was encapsulating the entire outside. They are nice but not impervious to denting or cracking. Tape should make the corners a lot toughter if that what you are looking for.

Ed

[Geron]

Why do you want to use glass on the seams? Is it because you think they will break? Think about if it is really necessary. Using fiberglass tape will involve a lot of sanding to blend it in. I used that method in boat building but it might be overkill for a box. Or it might make for some nicely rounded strong corners. I just radiused (radiated?) the corners with a router and soaked epoxy into them as I was encapsulating the entire outside. They are nice but not impervious to denting or cracking. Tape should make the corners a lot toughter if that what you are looking for.

Ed

You're right. I was thinking Mike used glass on the joints in his generic benroy. Reviewing the plans seems he did not. Just filled all defects with epoxy filler after a good bath of CPES.

Thanks for the heads up.

g

[Esteban]

Joanne completely glassed, then painted, the Desert Dawg. Her steps are well documented on her web site http://www.asolidfoundation.com/