The Poet Creek Express - Foamie Hybrid

[KCStudly]

Back to the build.

The buckle is back.

When I arrived at Mecca today I found that the upper part of the fiberglass patch had sheared away from the panel. The white area corresponds precisely to the spot where the crease/rift in the panel is and everywhere above it.


At first I thought, “holy crisp” (the ‘G’-rated version), did I do such a poor job of filling the weave?” but then I remembered what it looked like the day after application and the pictures, and I knew something else was going on. I took the long bladed utility knife, slipped it in behind the flap and cut the loose section off cleanly.


You can see the pattern from the weave in the epoxy that stayed on the panel, and the weave was clearly impregnated, so the only conclusion I could make was that I had not made the patch large enough to handle the load and it just sheared. Nothing to do but sand the edges fair a bit and bring the larger sheet of FG from home next time.


The buckle is back, dagnabbit, and it isn’t going to go away this time.

In the previous pic you can also see that I pulled the wooden washers out of the front radius (one by one) and reinstalled the screws flush.

This is that spot by the smaller buckle where the screw popped thru while we were doing the front radius glue up. I added additional screws above and below it just to be on the safe side.


I decided that this was a relatively harmless spot to try the old sawdust and wood glue (TB2) filler trick. It’s going to get covered over by foam anyway, so I probably needn’t have bothered, but I had a couple of bags of sawdust saved so I figured it was a good spot for a test.


I’ll come back to the front later, fair this spot and seal under the lower edge of the ceiling panel flap with a bead of vinyl caulk, just to be sure.

Next I started fitting the hatch ribs. Just clamped on to the side walls with some 5 mm spacers to start. Took a fair amount of time to get them started just right, so that they were both even from side to side and up and down while being flush everywhere (or at least a little proud, not low).



I finished up the evening by cutting the hinge spars to final length, matching the cabin width. Measure once, cut and fit each 4 times to creep up on it, exactly right!!!


Rather than fitting the galley counter now (to help stabilize the wall wings) I think I’m going to install a temporary strut that matches the counter edge piece in length. I kind of designed myself into a circle fastener-wise on the counter; no way to drive the pocket screws holding the spar to the walls after it is screwed to the edge of the counter sub-base.

Next time I plan to rabbet the hinge spars so that they will cap the edges of the skins, maybe lay the glass on the front if the piece I have is big enough.

[GPW]

That buckle ... grrrrrr!!! It’s the little stuff drives you crazy !!!

KC for years now we’ve believed bent plywood is not the best idea (ours always failed/split sooner or later) ... unless it’s specifically made to do that ... (which we haven’t tried yet. ) JMHO, it seems common gray chipboard ( a wood product) in the correct thickness does a more uniform job , bends easier , and really sticks to foam like crazy with TB2. For a nice inside look you could just cover it with Leather (or “pleather”) .. I know ! Even more “hybrid” ...

[KCStudly]

Pesky wood, has a mind of its own!

[GPW]

You ever tried “bending” plywood... ??? But that seems doomed to fail too eventually .... The only way to stabilize the Tension side of the bent plywood is to add a skin .. like a fabric , or fiberglass, something ...

[KCStudly]

You ever tried “bending” plywood... ???

Nope, this is my first rodeo!
I tried to tell you guys and gals, I'm just a novice wood worker, hardly any experience at this stuff... least when I started, anyway.
Hind sight is 20/20. If I woulda, shoulda, coulda I would have: A) kerfed the outside of the radius, B) used two layers of thinner ply, C) built something entirely different, like a screwed together and painted flat slab plywood Weekender... (blah, blah, blah, etc., etc.). (Not that there aren't plenty of highly detailed and very nice Weekenders out there, just saying, the design is simpler and proven... no bending.)


But I paid my nickel and here I sit, so on with the show! In the grand scheme of things it is merely an annoying blip. I'll do better next time(!?! ).

But really, I am happy for the experience and expect the rear hatch to go easier due to the looser radii (at least the bending part... still scratching my head a little on the construction sequence). That front curve was the worst of it at 13-1/2 inches.

[GPW]

No excuses at this point !!! .... you’ve done a Most SUPER Job all along ... That buckle’s just one little annoying thing that will NEVER be noticed ... No worries ... ( I’ll never tell)

[eaglesdare]

looking good!

[KCStudly]

Thank you Louella! And thank you, too, GPW.

[GPW]

KC, I’m still curious how the foam is going to go on ... guess we’re getting close to that eh ?

[KCStudly]

KC, I’m still curious how the foam is going to go on ... guess we’re getting close to that eh ?

Eh, maybe. According to Albert Einstein, time is relative.

Since the hatch will get foam applied, too, the plan right now is to build the hatch frame with its inner skin and then cap everything off with foam. Better work flow that way.

I did some impromptu testing of the 3/4 inch foam and it will bend enough to do the gentle curve on the main part of the roof. The tighter areas will likely be kerfed. Two (2) layers of 3/4 thk foam equals 1-1/2 inch, matching the rest of the cabin. Haven't decided on a glue yet. As I sit here and mull it over I'm thinking that most of the "bays" between roof spars are relatively narrow; if I make a stretcher out of a couple of 2x4 strong backs attached to the long sides of a slip of the thin ply (or luan) I might be able to clamp that on top crosswise (using pipe clamps hooked under the floor) to clamp and form the foam to the profile. If I use GG (my current thinking) that might be enough to hold the foam down and keep it from expanding out of the bays. Maybe just overlap the spars and temporarily screw down into them like a temporary outer skin, except I would be able to reuse the same long narrow piece of wood over and over again, so long as I protect it with a release ply of plastic sheet, or maybe even paste wax.

[lthomas987]

I had plenty of luck with packing tape holding my gorilla glue and foam. I used long dry wall screws and bamboo skewers for aligning things and pulled them out when things were dry.

[KCStudly]

You know(?), I haven't actually tried that tip yet. The thing is that most all of my foam joints, except for butts, are to wood, so there really isn't anywhere to stick a skewer. I have a bag of them in the loft, but haven't had a need to pull them out.

For the roof, I basically need to fit and glue individual pieces to the top of the ceiling panel and the sides of the spars. I might end up using the PL spread with a notched trowel.

Decisions, decisions.

[KCStudly]

.
Back to the front.

I ran around after work today, stopping at the marina near work to look for some glass cloth (only small patch kits available), then went to Defender, a wholesale marine supply house. They had the 6 oz cloth I was looking for in a 60 inch roll, so to cover the 63 inch wide panel I bought 2 yds and cut it down to fit.

I ran the top of the sheet all the way up to within about an inch of the first roof spar, leaving a little room for some masking tape to hold and ‘hinge’ the cloth in place, while also avoiding the areas where hardened wood glue was smeared at the base of the spar… didn’t want any issues with adhesion. Then at Karl’s suggestion, I marked along the sides, and across the top of the front flap before cutting the cloth to final size using the tractor swap meet scissors (they did a fine job!).

I didn’t get any pictures up to this point because I was discussing the process and techniques with Karl. An invaluable distraction, as he has lots of experience with FG, carbon fiber and Kevlar composite construction. The two biggest things he provided were the use of this digital battery powered scale, for accurate mixing, and the experience to know how much epoxy to mix for the size of the job, without mixing too much and wasting it, or too little and running short in the middle of the job.


We poured 400 grams of West 105 resin and 100 grams of 206 Slow hardener into a large DD iced coffee cup (maybe 2+ cups total) and mixed it well with a paint stir stick (which in retrospect I can now see is completely WRONG!!! Should have been leaner from 5 or 6 to 1… ARGGGHHHH … should have had Karl check my math closer… I’m a dumb A$$... ). Then I poured it into a plastic lined roller tray and used a standard 9 inch roller with a roller sleeve intended for epoxy. It had very short, straight, and sparse hairs, compared to a matted nap paint roller. I think this design puts a lot more of the product on the work and doesn’t waste as much as what would be absorbed into the other style.

Here I am rolling out the epoxy on the front radius. You can also see the cloth folded up on top of the cabin.



Here we have laid the cloth back down into the epoxy and daubed it off with a couple of chip brushes.




I can’t believe I made such a dumb/common mistake (… oh yes I can!). Man I hope it cures okay.

[KCStudly]

Maybe I'm just remembering wrong?

Maybe it was only 80 grams of hardener?

[atahoekid]

I know for a fact that your not the only person who has screwed up the math while working with the ratio of epoxy to hardener... Let's just call that person someone I know rather well... If you were off too far, it might never cure at all.... Hope that isn't the case.