Too Much Epoxy On Glass Tape
June 11, 2017 at 5:29 pm #886comccoyParticipant
Having never worked with epoxy and/or fiberglass I think we have a mistake with our first glue ups on the puzzle joints last night. We worked steadily and with 2 small batches of epoxy so I don’t believe we had a temperature issue (about 74-75 F in our garage). It looks like the issue was our impatience with getting “just enough epoxy to make the glass tape go clear” and we did not know how long it would be before it saturated. I think we really laid it on thick. It cured under the poly sheets and seems to be thick and glassy.
My concern is if we try and flex these in to place in the mold they wont and we risk cracking the plywood around them. Can we just sand the epoxy down to an acceptable level? Should we sand off completely and try taping and epoxying again?
To avoid this in the future do we squeeze out all the excess if it gets super saturated?June 12, 2017 at 10:31 am #891Bob D.Participant
Looks fine to me. Just sand smooth and don’t try to sand into the glass. Leave the low spots low and fill in later.June 12, 2017 at 11:08 am #892stevieParticipant
It seems to be more a cosmetic problem. I really can’t say if they weaken the joint. If the bubbles aren’t dealt with though, they’ll always be visible. Not an issue if that’s the interior side. Or if you plan to paint the camper. If you’re not using the suggested epoxy spreaders, purchase some before continuing. They’ll go a long way in removing bubbles and later in removing excess fillets.
Your skill in applying epoxy and fiberglass cloth will increase exponentially as your build progresses. This feller has all sorts of how-to epoxy fiberglass onto boat hulls: https://www.youtube.com/watch?v=nTmGLqhgnoM
Same principles for our builds. Many more like videos on youtube. Others show how to create fillets and smooth fiberglass cloth. They were very helpful to me.June 12, 2017 at 12:25 pm #893restonthewindParticipant
We’re at practically the same point in the build. I had a similar problem when my epoxy thickened too much to saturate the fiberglass tape. My garage is much warmer than yours at peak temperature, though I was working in the evening when the temperature was closer to 80 than 90. The epoxy eventually thickens regardless of the ambient temperature, and I simply waited too long before abandoning the thickened epoxy for a new batch, or I mixed too much. I mixed less than the 8 ozs. the manual suggested, but I presumably also worked more slowly than the manual anticipated.
Three of my joins look good, but one looks at least as glassy as yours, and I have a patch of unsaturated tape about the size of my thumb. I agree with Bob that your join only needs standing, and any cosmetic issue is negligible, since you’ll presumably cover it with foam or other insulation.
I don’t think the extra epoxy increases the chance of a crack. One of my top panels had an apparently flawless join. The other looked more like yours even after sanding. The one with the flawless join cracked when I tried to place it in the mold. Pictures are in the “Omitting the galley” thread. The crack was not near the puzzle joint, so I don’t think the strength of the join had anything to do with it. I’m still waiting for feedback from CRC on how to proceed.June 14, 2017 at 5:56 pm #918rovineyeParticipant
My first puzzle joint looks about like that. I am working on hatch supports now and my skill, while not mad skills, are definitely better. Like Stevie says, your subsequent work will improve vastly! I hate the look of that joint every time I look at it but I know it will be covered by headliner so I try to ignore it.
Eric had a suggestions about rolling up wetted tape before laying into place. I responded to it today so it should come up in a recent response list. I strongly advise that method! It is not as messy as it would seem.
- This reply was modified 3 years, 10 months ago by rovineye.
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