ruderunner
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Post by ruderunner on Jan 22, 2017 5:06:49 GMT -8
So in thinking about the profile of the trailer we'd like to scratch build, it occurred to me that it would be good to know what is practical so we don't design something impossible to build. We're going for a canned ham look though bigger than most. You all might call it more toaster but the concern is the same either way.
Basically the question is, what radius bends are easy to make in say 1/4" and 1/8" plywoods?
I realize that there's tricks to getting tighter bends like: steaming, kerfing or laminating but I'm thinking just in modified ply.
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Post by vikx on Jan 22, 2017 21:11:18 GMT -8
I don't know the radius as I normally have hams and it's built in, so I copy the curve.
1/8" plywood is very important if you have tight turns. I've tried 1/4 and haven't had good luck at all.
Maybe someone else will chime in...
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ruderunner
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Post by ruderunner on Jan 23, 2017 4:13:23 GMT -8
I figured that 1/8 would bend tighter. Care to hazard a guess?
I'm thinking that a small canned ham probably has 7' sides, if the curve on constant that would be a 3.5' radius. Toasters seem to have much tighter curves at the top, I'd guess as low as a 1' radius.
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Dad Rambles
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Post by Dad Rambles on Jan 23, 2017 5:45:30 GMT -8
I would say, based on my experience, that it REALLY depends on the specific plywood. Most particularly, the core material, and which way the grain is running.
There is a post on here about Columbia Forest product "Radius Bending ply". It is 1/8, and will bend a pretty tight radius, I would say 6" or less. Very "loose" stuff.
The 1/8 ply I used wouldn't do do anything near that, but it does work for my 62 shasta. Conversely, I bent some 3/16 underlayment (while wetting and heating) to a 24" radius on my teardrop and that was about at it's limit. Also some 1/4 oak, to that same curve, and it was near it's limit as well.
End of the day, pay the $$ and use the right wood.. It will be worth it in the end. Believe me, I've gone back and forth on this many times for different projects. I paid 62 bucks a sheet for the stuff I have now, but I couldn't be happier with the results it produces.
Just my 2 cents.
Brian
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ruderunner
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Post by ruderunner on Jan 23, 2017 14:51:43 GMT -8
Well that's some good info. I'm not thinking anything near a 6" radius, for that I'd just cut some pipe!
I'm looking for easy building, if I can only get down to a 2.5' radius then that's what it will be. But I don't think I'd even go that tight.
Was mostly looking to see if something like a 4' radius would be a major hassle or easy.
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roadtripper
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Post by roadtripper on Jan 25, 2017 21:36:21 GMT -8
Why don't you get one sheet of 1/8 ply and a sheet of 1/2 or 3/4 cdx ply and jig saw the radius you think you want and see how the 1/8 bends around it. Play with the radius one way or the other till you get something that feels good.
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cannedkev
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Post by cannedkev on Jan 31, 2020 19:10:13 GMT -8
I just tonight installed the radius front wall to ceiling panel in my '57 Corvette using 1/4" birch plywood paneling. It's about a 14" radius and was pretty tough to do. I built a jig to bend the plywood over using 4 ratchet straps to bow it around the jig. I did it in two steps to keep from cracking the plywood. I put wet towels on the sharpest part of the bend and let it set over night. I then used a heat gun to heat/dry the wood. It worked, but it wasn't an easy task. If I had to do it again, I would get the bendable plywood.
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ruderunner
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Post by ruderunner on Feb 2, 2020 4:14:56 GMT -8
Since this thread popped back up and I started doing bends i guess i can add some information.
I worked on the tail profile the last couple weekends and it seems that quarter inch maple ply with a poplar core can do a 4 foot radius without any tricks if run side to side. I tried it long ways but it snapped in the middle. Wetting and kerfing of course would allow a tighter bend.
I have a 4x8 sheet of pine eighth inch that im going to use for the 2 foot radius for the forehead. Its a single ply and so far seems very flexible. It will be hidden behind cabinets so im not too worried about appearance. I also have a couple 2x8 pieces that I can use to make up the thickness difference.
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mobiltec
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Post by mobiltec on Feb 3, 2020 9:37:03 GMT -8
I'm doing an all plywood 1947 trailer that was originally wrapped with 1/4 inch and I'm sure they steam bent it to get the radius. I'm sure of it because I can not get 1/4 inch plywood to bend as tight as needed. So I'm using two layers of 1/8 inch. Foster Wayne gave me the idea with a trailer he did and it works great. The first layer can be what ever you want the finish to look like. If it's going to be shellacked then so be it. The second layer is luan because it is just there for thickness and not what it looks like.
The trailer Im working on has solid plywood walls which is why the manufacturer went with 1/4 inch on the wrap. It's part of the structural integrity of the trailer due to very little framing inside on the exposed walls. If you are doing framed walls there is no reason to go with 1/4 inch on the wrap. Just go with 1/8 framed wrap like all the rest of the manufacturers in the world have done in the past. Tried and true.
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ruderunner
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Post by ruderunner on Feb 3, 2020 15:03:14 GMT -8
Im going quarter inch for availability and cost. What I've found for eighth inch is more expensive, smaller sheets and almost an hour drive to get.
Ah, the freedom of not restoring.
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mobiltec
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Post by mobiltec on Feb 3, 2020 17:52:46 GMT -8
Good luck. Freedom to not restore? That's what this hobby is all about. That's what this forum is all about. We restore vintage trailers. Most of us don't build or design them. It's all about nostalgia for the time period in my opinion. I'm into mid-century-modern and antiques. You can't build an antique. If you do it's then called a replica. What you are doing is great. But it's a replica. It's not a vintage trailer.
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nccamper
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Post by nccamper on Feb 4, 2020 20:20:49 GMT -8
An interesting point: “You can't build an antique. If you do it's then called a replica.“ Is a vintage camper still vintage with new skin, new walls, new floor, new wiring, new plumbing, new framing, etc? What percent of the camper can be replaced without crossing the line? 10%? 50%? If all that remains are cabinets, windows and frame, is it a reproduction with vintage parts? The campers I’ve worked on range from 10% new (1962 Shasta Compact) to 70% new (1959 Airflyte). So I guess the first was a restored camper and the last was a knock off with a vintage title? Ruderunner always called his camper a new build with vintage design elements. I think that belongs here. Ideally, I’d like to see everyone work on 1950s vintage campers like Larry has in his videos done 10 years ago. 20% new, 80% original. $500 purchase price True antiques. I guess it's an academic debate since they don't exist anymore. Heck, I’ll gladly buy the first 1957 Shasta (with a title) in my home town that only needs 80% of it replaced.
Will it be an antique when I'm done? No.
Will it be as special as a camper 80% original? No.
But I'll take what I can get.
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mobiltec
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Post by mobiltec on Feb 4, 2020 21:21:28 GMT -8
It's all subjective... My Jewel will be all new but for the chassis and the cabinets and hardware. New walls, new wrap and new skin. It's a restore in my opinion. Nothing wrong with building a replica. I'm going to build one myself.
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ruderunner
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Post by ruderunner on Feb 5, 2020 17:38:16 GMT -8
It just a variation of Washington's axe.
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mobiltec
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Post by mobiltec on Feb 6, 2020 6:59:05 GMT -8
It just a variation of Washington's axe. Theseus’s paradox... Very good comparison.
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