Tom & Shelly's build

[Tom&Shelly]

"I'm hoping the epoxy, if we put it on thick on the coats after laying the fiberglass, will self level and help fill in the ripple on the top"

pox really doesn't level well on it's own

no need to ask how i know and it wasn't pretty nor was it easy to resolve

pox is best applied w/ a squeegie in thin layers and hot layering is my preferred method when multiple layers are in order

when brushed or rolled on the stuff has a bad habit of turning a project into something looking like a relief map of the Rocky Mtns

sw

Thank you SW,

I think Shelly and I must "do" epoxy differently than most, judging by the comments on tnttt. For our teardrop walls, which we are happy with, we first put down a thin coat of epoxy. After it dried enough so it wouldn't stick to the fiber glass, but before the 24 hour time it would have dried to the point where we would have wanted to sand it for a mechanical bond, we laid the glass out and smoothed it carefully. Then we rolled more epoxy on using white foam rollers (also how we applied it initially). On the first coat after laying out the glass, we were careful to keep the glass flat on the surface, and put on enough to wet out the glass.

Then, within 24 hours between each coat, we rolled on about three (four?) more coats. Some spots were higher, but after it dried for a few days, I went along and wet sanded (by hand) with 220 grit sandpaper. A 10 x 5 foot wall took maybe three nights for me to sand (few hours per night). Maybe that's more sanding than most would want to do, but it seems like it came out okay. Nice and flat.

On some shelves we made that way, we had a little trouble with some primer sticking later, but that may be because I forgot to wash any amine off. Also, I can see the fiber weave under the epoxy in a few places on the walls (which, of course, we haven't painted yet), but the surface is nice and smooth. I'm wondering if some of the epoxy got under the glass and lifted it from the surface? Maybe not as strong that way, and it would have been bad for a woodie, but I'm thinking it'll probably be acceptable for us.

We only know one couple who built a fiberglass boat, and, as far as I know, they don't know anyone who did it in person. So we're going by what we read in Steve Fredrick's manual and on the web, and now by extremely limited experience. In other words, I'm not sure I know what I'm doing, though the results seem good. Anyone see any "red flags" is what I've described?

Tom

[Tom&Shelly]

and even more skeptical of my ability to sand it much flatter later.

Use a long sanding board so that it floats on the high spots.

If you are hesitant about Elmer's holding power then use thickened epoxy* applied with a long trowel so that the goo is only applied to the valleys. If you go this route, give it a thin coat of unthickened epoxy first.

Tony

*I use cabosil for a thickener but micro balloons make for a relatively sandable epoxy filler. They also are used to increase the radar transparency of some aircraft and that would be damn handy if you plan on doing 65 in a 55 with your teardrop.

Thanks Tony, what ratio did you use for epoxy to cabosil? I'll order some and we'll try that, probably with our last coats of epoxy over the glass. I'll sand it with a long block.

Does cabosil thickened epoxy also work better on vertical surfaces?

Tom

PS--The local hardware store didn't have Elmer's wood filler so I used the DAP version to fill the screw holes. 6 hour drying time, which is longer than I remembered for the Elmer's, which is why I'm posting these now

[tony.latham]

...what ratio did you use for epoxy to cabosil?

Just keep adding it to the mixed epoxy until it's as thick as peanut butter.

But West Systems suggests mayonnaise for fairing.



Tony

[Tom&Shelly]

So, with 20/20 hindsight, it's difficult to defend doing something this dumb. But, I thought I'd give it a try. Specifically (and, as an aside, now that I've composed those two sentences, I think I may be able to re-use them in many other contexts): Routing the 3/8 inch round over in the roof/wall interface without first dealing with the ripply roof...



Yikes! Looks just as bad from under the top looking up, although these pictures came out better.

The problem, of course, is that the bearing on the round over bit rode on the ripply top. So, I figured I needed to minimize the ripple. As long as I only sanded it down, and didn't build anything up, I could re-run the router and it should only take more material off. This, in fact, worked. I only sanded a few inches from the edges, and so the roof has sort of a crown, although it's difficult to notice (I hope!)

My 1/8 inch Baltic birch comes with a 1/16 inch core, and two 1/32 inch face sheets. I sanded clear through the face sheets in some places



but the roof line looks smoother



I suppose I should take some pictures at the same angle as the first two. (Coming soon.)

I used this oldish hand sander with an ~8 inch long plate. Since the ripple went between screws four inches apart, it smoothed the high spots nicely.



Spent a few hours on it yesterday. I hated sanding off so much, but I hope the fiberglass and epoxy makes up for the thinner substrate.

After doing that, and cleaning up, I decided to wait until this morning to try re-rounding. So I spent an hour with 5 minute epoxy and glued the inserts into my Kreg-jig holes in the wall-to-floor interface. Totally unnecessary, but I like the touch.



Actually, someday, we may replace the mattress with something that folds up so we can sit up during the day, and then they will show.

Tom

[Tom&Shelly]

OK, lighting is different. It looks much better now, trust me!

Before:

After:

[Tom&Shelly]

After more than a month of other activities, Shelly and I are back working on our Benroy style teardrop!

After spending the morning cleaning the dust in the workshop, we applied a coat of epoxy to our roof and galley



Caught the light just right (wrong?) in this next shot to show where the temporary screws held the Baltic birch down, while the PL Premium pushed the rest up



What I should have done was to glue the flat horizontal part of the roof with TB III, and the curved and vertical part with PL Premium. Oh well. Still hoping to fair it up, after glassing, with epoxy, possibly thickened with cabosil (fused silica).

It is below freezing outside during the night (low 40's during the day), but we're running the electric heater full time in the shop and hope to have this first layer cure in the next day or two. Our plan is to let it dry completely (possibly also using a little epoxy and phenolic to fill in a few splinter holes that the wood putty missed), wet sand, then lay out 4oz fiberglass for a few days to conform to the compound curves, then wet out the glass, and add several more layers on top of that. Shelly's looking on the interwebs to see how to do this compound curve thing. I'm guessing we'll cut (or tear) the fiber glass where necessary to conform to the curve.

We used our preferred method of application--not preferred by many here--of using a white foam roller



It worked well for the first coat, leaving no drips on the vertical surfaces. We anticipate that becoming more difficult for the coats after first wetting the glass.

We had a moment where we thought we should go out and buy some plastic disposable paint roller pans, but realized we had plenty of macaroni and potato salad containers (saved for holding small parts) and the lids would work perfectly



Took three 6 oz batches of epoxy to do this job.

If we get the roof epoxied over the holidays I'll be happy. I just retired, but will be working part time as a consultant, for those times when they don't want to screw it up themselves. Hoping that'll leave me plenty of time to finish this thing before Summer. Once the roof is done, I'll test fit the galley hatch with hinge, figure out the gas strut mounting, and build the galley and electrical box. Those are the remaining big jobs.

Tom

[tony.latham]

Still hoping to fair it up, after glassing, with epoxy, possibly thickened with cabosil (fused silica).

I think I'd fair it now before it's glassed. Otherwise, you may sand into the glass too deeply during that process.



But it looks good. And, by the way, congrats on the retirement. Sleep in. Don't shave. Take naps. Screw off. Leave your fly unbuttoned.



Tony

[Tom&Shelly]

by the way, congrats on the retirement. Sleep in. Don't shave. Take naps. Screw off. Leave your fly unbuttoned.



Tony

Thanks Tony! I was already doing some of that stuff before I retired!

Tom

[Tom&Shelly]

Still hoping to fair it up, after glassing, with epoxy, possibly thickened with cabosil (fused silica).

I think I'd fair it now before it's glassed. Otherwise, you may sand into the glass too deeply during that process.

Tony

We followed your advice Tony, and Shelly started to fair it today. She watched a few Youtubes from boat builders and decided to make a peanut butter thick mix. I thought it might stick to the scraper and pull out, but it worked just fine for her. She deliberately did relatively thin layers, so plans to go back tomorrow and finish the job. I'll still wet sand before we put the glass on, which looks like maybe Christmas Day or shortly after.

Shelly seems to enjoy this part much more than I do, so we'll leave her in charge of glassing and finishing, and I'll stick with cutting the wood, finishing the electrical work, and crawling under the teardrop to epoxy the part we missed along the edges when we thought we were going to have a skirt.

We still have to see how well the 4 oz glass takes to the compound curves. I thought about leaving the roundover between the walls and roof unglassed, with just the epoxy, but had bad dreams about us being a thousand miles from home and spotting cracks there though the Monstaliner. Probably wouldn't happen anyway...

Tom

[tony.latham]

We still have to see how well the 4 oz glass takes to the compound curves.

Where are those compound curves? I just see the profile curves.

Tony

[Tom&Shelly]

We still have to see how well the 4 oz glass takes to the compound curves.

Where are those compound curves? I just see the profile curves.

Tony

Well, the transition from roof to wall is a 3/8 inch round over. But then in the front there is also the 19 inch radius and in the back the 48 inch radius. Our thoughts are to wrap the glass on the roof to the top of the walls and then fair it out on the walls, over the existing glass.

Tom

[tony.latham]

Well, the transition from roof to wall is a 3/8 inch round over.

It may work. If it wants to lift, keep pushing it down as the epoxy begins to cure. If it fails, buy a fresh Surform blade and be done with it.

I'll keep my fingers and toes crossed up here.

Tony

[Tom&Shelly]

We (Shelly) spent several days fairing the dimples in the roof, until we called it "fair enough" and laid out the glass. The straight edge still saw ripples in the roof, but our eyes couldn't. So we may get a little rain water puddling, but once enough accumulates, it'll run somewhere--probably toward the galley hinge, since my acid reflux dictates we put a slight angle on the bed. (Seems to be a fairly common thing for us on this forum.)

We let the glass rest on the roof for a day or so, and Shelly cut made a few cuts to relieve the stress on the front compound curve. She studied a few You-Tubes, and had a procedure in mind for epoxying the glass, and I didn't have any better ideas, so mainly watched and helped while she did it all.

She started by using a toothbrush to apply epoxy to the curve on the Starboard side



We then gave the epoxy an hour to begin to dry (love doing this in the Winter, were we control the temperature!), and she applied more to the side. She tried a fresh toothbrush, but decided a white roller worked better



Worked well, and the glass laid right down. We have a bit of overlap at the cuts, but plan to fair it out with cabosil laced epoxy after a few coats of pure epoxy.

Shelly then used the roller to work across the roof to the port side curve.



At that point, we gave it another hour and she applied epoxy to that curve using the toothbrush again (fresh brush each time--six for a buck at Wallmart). (I'm going to try the left over brushes for their intended purpose--why pay more?) We then waited another hour, and she rolled the port wall



The one picture there shows the cuts and overlap of the glass on the front curve.

We are real happy with the way this came out so far. We plan to apply three or four more coats of pure epoxy, letting it cure, then wet sanding it smooth (my job), as we did with the walls. We'll then fair the sides with epoxy and cabosil.

We also have the hatch to do, of course. We wanted to see how this went first, so we just laid the glass on the hatch and are letting it conform right now, so we'll be a day behind on that one. As it happens, we used up the first roll of glass on the roof, and had to start another one just for the hatch. Oh well!

I must say, after watching Shelly do all this work yesterday, I was too tired last night to post this, so the post waited to morning!

Tom

[tony.latham]

It surely looks great. And I'm damn glad you didn't have a problem rolling it over the edge.

She tried a fresh toothbrush...

I thought you were joking when I first read about using toothbrushes.

But anywho, nice BB-gun-proof teardrop.

Tony

[noseoil]

Looks like it's laying down pretty well. Glad it was faired first, glass is a real booger to sand when it's lumpy or uneven, bad enough when it's really flat. Should be relatively easy to finish with the prep being done properly. Kudos to Shelly for spending the time to get it right!

Second the winter work for epoxy, I had some on a small boat I did in Tucson, which needed to have the resin & catalyst in a small cooler in an ice bath. The stuff was kicking off too fast, so both resin & hardener ended up in the cooler just to keep it working long enough to wet out the cloth. Glad to be in NM now.