The Poet Creek Express - Foamie Hybrid

[eaglesdare]

i can't wait til the shell starts. great job so far!

[KCStudly]

No, GPW, it's 20 sheets of thin plywood, 5 mm or 3/16 inch. Sorry to jump back and forth talking about how easy the foam was to figure and how tricky the ply would (pun?) be. The foam is only 7 sheets of 1-1/2 thk 4x8 plus 1 sheet of 2x8; and 1 sheet of 3/4 thk 4x8, as mentioned previously. I think I can squeeze the plywood down some.

The problem with the plywood is that I have so many pieces that are over 60 inches long by over 1/2 a sheet wide, and all of the shelf/cabinet bottoms are long, too. I'm going to go and split the lengths of the shelves and cabinet bottoms in half (plus a bit for scarf joints... or maybe just in half for a fiberglass/epoxy reinforced butt joint), let the grain fall where it may on these pieces, and see if that utilizes more of the 43% waste that Max Cut said I would have.

I did rummage around in the Max Cut software some more this evening and found the "reports", or print out section. That makes it a lot simpler to figure out than the initial optimizer screen shot. Each different sheet layout (there are 12 of them) is depicted with the name of each piece in situ on the diagram and a table listing the sizes for each piece by name; how many sheets that particular diagram applies to (some layouts repeat for multiples), etc. You can even print labels to apply to the actual parts so that they're much easier to keep track of after cutting. Let me see if I can include an image...

It worked.

This one isn't too bad. Most of this sheet is used, but there are only so many of the little pieces and every big piece needs another sheet. I want the grain of my walls to run vertical, but that isn't so much of an issue as all of the floor, front, ceiling and hatch pieces that have to span over 60 inches. There are at least eleven (11) of those that need to start with a full sheet. I was trying to avoid scarfing, but may have to take another look at that.

Hmm, maybe I can get "Rover" Mike to get one of his guys to push all of this stuff through his nice commercial table saw. That would make my time on his project worth it!

If I haven't said it before, you're fabrication skills are top notch!! Wish I knew my way around a metal shop even half as good as you

Thanks, Zach. I've been forcing my will on metal for at least 30 years now (damn, that makes me sound old ). Every time someone pays me a wonderful compliment I am left wondering about the skills that they possess and I don't. Everyone has the ability to be good at something! One thing I have always said is, "If you can show me how to do something, then I must be able to do it, too!"

I can't wait til the shell starts. Great job so far!

Eagle, me too! Thanks.

[KCStudly]

Okay, we're whittling it down.

I made copies of the floor and bulkhead assemblies (the 3D models) and reskinned them (virtually) using several smaller pieces skarfed together. I got it down to 15 sheets and only 23% waste. I did a quickie adjustment (flying stab) at changing to scarfing the ceiling panels together, but that only made the individual panels slightly wider with no sheet savings so I think I'll just stick with butt joints there to keep things simpler (huh, huh...huh, huh...he said "simpler" - Bevis & Butthead voice).


I'm getting there.

[KCStudly]

Shock absorbers were sitting on the front porch waiting for me when I got home. I'll post pics when I start working with them.

They are very short when fully compressed and do not have a great deal of overall travel. Probably perfect for std. trailer springs and hangers, but may end up being a mis-match to my Jeep and off road suspension parts. I think I might mock the suspension up and load the frame down with a couple of barrels of water to see what the installation heights and travels look like. Plan 'B' would be a set of inexpensive Jeep YJ rear shocks. The trailer axle is a lot lighter than a drive axle, even a little D35, but the Jeep shocks should be reasonably close (compliant enough) given that they are matched to the springs, and the load ratings of the springs are right in the ball park for the trailer.



Tomorrow I have my annual eye exam after work and am in desperate need to upgrade my work/safety glasses to bifocals (there's that age thing coming out again ... safety glasses don't do much good when you are looking over them to see things that are up close).

Friday I will work to finish the plywood schedule and try to start picking off the lumber list. I need to decide how I am going to build the reinforcing rails for the edges of the galley side walls, and if I am going to use plywood or built up ribs for the hatch framing. For the ribs I am thinking that I should use the drops from the 5 mm ply laminated together with TB2 and get "Rover" Mike to CNC router them out (or at least a template)... but then again I had not intended to use any blocking or spars in the hatch field, only at the hinge and bottom end, so the skin would have to be fastened into the edge grain of the plys (should try to avoid that). Option B is to miter 1 x 3 or 4's, biscuit join, then router to shape, but that sounds time consuming and like more skill would be required to get good fits.

Any opinions?

I do have access to powered miter saws, an edge joiner and surface planers, and I own a biscuit joiner that I have used a few times with acceptable but mixed results...joints aren't always flat and even.

I know that drywall screws are frowned on by some due to concerns about vibrations and dynamic loading from road undulations causing the heads to break off, but, if I decide to go with plywood ribs, I wonder if they would be better for securing the skin in my hatch application since their thin shanks would tend to disrupt the ribs less. Think about it, thin ply wrapped onto plywood ribs, glued and screwed with drywall screws, then 1-1/2 thk foam glued over that, then canvas glued and wrapped under the ply up to the outside of the first rib.

Am I crazy to be thinking drywall screws? What would work better, pneumatically driven staples into ply edges? That doesn't sound correct.

[GPW]

KC, how about brass screws ? ... Many an old wooden boat was built with brass screws , and they survive the pounding a boat receives... Drywall screws are pretty brittle ... Just a thought ...

[Wolffarmer]

I largely used deck screws. It was them or real wood screws. No problems yet at about 15,000 miles and a whole mess of rough road and some 4x4 road.

Randy

[KCStudly]

Thanks guys, I was more concerned with the screwing in between plys issue. Coated deck screws are probably what I will use. I see no advantage to the brass screws. They will never be seen, so cosmetics are not an issue, and are softer and way more $$$ than necessary. If I was worried about corrosion I would use stainless bought in bulk.

I was running an errand this evening at a local shopping mall and as I was coming out I noticed a young man pulling in driving a well used Jeep YJ. He happened to pull in just a couple of spots from where I was, so I decided to see if I could take a look at his rear shocks to see if they had a post style upper mount or the bar-thru-eye style. Gave him a minute to clear out, then went over to take a peek. What's wrong with this picture? (You'll just have to imagine what I was seeing, as that was just a rhetorical question... I didn't actually take the camera out.) Hmm, no rear shocks. The upper shock mounts appeared to have rusted thru at the mounting point and the shocks must have been removed rather than repairing the mounts. Good thing all of the roads here are smooth as glass with none of those infamous New England potholes or frost heaves... NOT!!!

[DJT]

If your looking for shocks, check out: http://www.monroe.com/assets/downloads/ ... hSheet.pdf
There's a bit to wade thru, but you can choose by extension/compression/mounting etc. I can't remember which ones I ordered, but I think they will be perfect for my build.

[S. Heisley]

I largely used deck screws. It was them or real wood screws. No problems yet at about 15,000 miles and a whole mess of rough road and some 4x4 road.

Randy

Thanks for that, Randy (Wolffarmer). That gives me confidence in what I did.

I was told to use drywall screws and I started to; but, I found out really fast that they would work their way right back out just from a little bit of movement. I can't imagine what would happen with miles of road vibrations. I looked at the Kreg screws and they looked a lot like deck screws. So, wherever I didn't use Kreg screws, I used coated deck screws and, unless they were plugged or glued in, I replaced every drywall screw that I had previously used with deck screws.

[linuxmanxxx]

I use deck screws the coated ones with the torx head to tie my walls together and frame and cabin together along with wood glue and use only the fine threaded drywall screws for most everything else needing to be attached and have had no problems with them backing out on the fine threads. I do use the deck screws to attach walls to floor and walls to walls and ceiling to the walls along with a liberal amount of TB3.

[KCStudly]

Thanks for all of the replies and encouragement to use deck screws for major joints.

Does anyone have specific experience with screwing through thin hatch skins into the edge of plywood hatch ribs? What is the best fastener method for this type of joint? Or should I build the hatch ribs up out of mitered and plate/biscuit joined 1x 3 or 4? I do not intend to have hatch spars or blocking, just ribs, ply skin, 1-1/2 thk foam, and glued/painted canvas skin.

[GPW]

The “correct “ staples might just work and be much easier/quicker ... have to watch your pressure too so you don’t drive em’ into the next county ... The staple principle is sound, but the work Has to be exemplary to work going into plywood edges , thinner than screws, less displacement of the end grain ... We’ve all seen what quick sloppy stapling can do ... Staples applied with the precision due to screws , should work the same eh ??? Only one thing ... if they’re in there correctly , they’re a real “xxxxxxxxxx" to get back out out...
Just thinking ... staples would be Lighter too ... gotta’ tow it around later ... lighter you make it , the more Beer you can haul ...

[Wolffarmer]

KC, if you use plain old plywood would be hard to get something to hold and match the work you are doing on the frame. If you could really plan it glue in dowels first then screw into those. Very unlikely that can really be done. Biscuit joining lumber together will take a bunch more time and I kind of wonder about the strength. Two things I think I would try is #1, use baltic birch plywood at least. It does look like it will hold screws better, easier to get your hands on. Or if you are getting some of the better plywood anyway could use that but I would not just just plain old AC plywood. full of voids and crap wood. #2. If have time I would take the 1x4 and resaw and plane them so I have a 3/8x4 or 3/8x3 ( or so ) then I would build a jig to cut the proper circle on the band saw and cut a mess of segments. glue these together sort of like bricks so they span the joints ending up with a rib 3/4 inch thick. maybe the outer two 1 1/8 inch thick. Could use light weight pine or other softwood for this.

Randy

[Wolffarmer]

Just thinking ... staples would be Lighter too ... gotta’ tow it around later ... lighter you make it , the more Beer you can haul ...

The more beer you can haul. The more beer you can share.



Randy

[linuxmanxxx]

Heres thinking outside the box. Just saw post about using steel conduit bent and welded for roof racks, why not use same thing for hatch framework? Weld some flat stock where your hinge attachment points are at and use thin foam glued in layers around it.