Q about sheet metal fabrication and adhesives.

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roland64

Q about sheet metal fabrication and adhesives.

Post by roland64 »

Hi everyone.Thanks for all the help in the past. I would like to fabricate a boiling trough(dimensions:8"x 8" x 48" long) for bentwood projects I make.I have a smaller metal trough(flower planter,30") I use for guitars sides and shaker bentwood boxes,however,I am going to try to make some steambent maple shells for snare drums(like the old Slingerland Radio Kings) which require 48" lengths of wood.
I have built a couple of 52" long wooden steam boxes,like they use in wooden boatbuilding and windsor chairmaking,however,the severe radius of a drum requires the wood to be at its maximum plasticity.The wood for the drum shells are 1/4" thick and I end up breaking them right out of the steam box.It just isn't getting the wood hot enough.
For the trough I would like to order some aluminum sheet(alloy 5052-h32) from Emco at 24" x 48" by .050" thick and use a high temperature adhesive(Flexbar autostic hi-temp industrial adhesive cement rated at 2285 degrees fahrenheit) to glue some angles of the same stock to facilitate creating the ends of the trough(the 48" standard length of the sheet stock isn't long enough to make bent ends for the trough,though the sides can be bent).Is this feasible?It is hard to believe glue will hold up to 212 degrees boiling temperature continually however this cement is rated at 10 times that... theoretically at least.
OTOH,I can obtain a 150 watt soldering gun from Harbor for $10.Would it be possible to solder the 16 gauge metal angles for the ends with one of those?That way I could solder the angles on.Kind of like they do for the corners of fish aquariums to some extent.
I know brazing would be ideal,however,I don't have an oxy-acetylene setup so I am try to circumvent that.
Anyways I am obviously green as a gourd.Thanks for any insights.Roland.
David_toledo
Posts: 147
Joined: Sat Jan 04, 2003 11:57 am
Location: Toledo,Oh

Re: Q about sheet metal fabrication and adhesives.

Post by David_toledo »

How about pvc plaltic pipe Or 3/4 plywood booth will work for a steam box
David
Gourdhedd
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Joined: Thu Dec 18, 2003 7:32 pm
Location: Austin, TX
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Re: Q about sheet metal fabrication and adhesives.

Post by Gourdhedd »

How about pvc plaltic pipe Or 3/4 plywood booth will work for a steam box
David

I've used 4" PVC sewer pipe before and it collapsed. I would say to use, at minimum, schedule 40 PVC.

For the aluminum joining question, how about using pop rivets with a dab of silicone on each one if you want a good seal? You need a little leakage anyway to prevent pressure buildup.
Gary
Rolly

Re: Q about sheet metal fabrication and adhesives.

Post by Rolly »

A wooden box should be all you need. Maple is a hard wood and you should find fresh cut green wood to steam bend. Figure on one hour per inch of thickness. After you get it bent, air-dry it for six months.
Rolly
Patenteux47

Re: Q about sheet metal fabrication and adhesives.

Post by Patenteux47 »

Roland, I may be way out in left field on this one but here goes anyway. "3 M" makes an epoxy type glue for body work ( 3 M Panel Bonding Adhesive ). I used it last summer to put fender panels on my old truck and it is as strong as weld. (I tried separating the seam with a cold chisel and hammer, NO WAY)

Just an idea [img]/ubb/images/graemlins/crazy.gif"%20alt="[/img]
roland64

Re: Q about sheet metal fabrication and adhesives.

Post by roland64 »

Hi everyone.Thanks for the response.
Sorry but I am not interested in building another wooden steam box-or pvc one which I also have.The one I have fabricated from plywood works fine.Steaming wood is much slower than boiling however.The wood must become saturated by the steam before it is fully plasticized.This doubles the time when compared to boiling.I have been bending wood for years and prefer to boil.It is quicker and uses less energy.
In regards to fabricating with the metal and high temp cement is there no one out there who has tried such a thing or has everyone simply had access to brazing equipment? Thanks Roland.
jpfalt
Posts: 982
Joined: Sun Jan 05, 2003 12:55 pm

Re: Q about sheet metal fabrication and adhesives.

Post by jpfalt »

Add some ammonia to the water and the wood will plasticise faster and more effectively.

Fine woodworking did a number of articles on both boiling and steming for bentwood projects.
Ralph_Monroe_Mi
Posts: 202
Joined: Sun Jan 05, 2003 9:33 am
Location: Southeast Michigan

Re: Q about sheet metal fabrication and adhesives.

Post by Ralph_Monroe_Mi »

Roland,
I believe your original question was loining aluminum by means other than welding. Here's a link to an aluminum soldering rod that uses a low temp soldering rod an a propane torch. I've used the product for some minor non structural repairs and have been satisfied.
durafix

The problem with sheet will be holding heat in. Aluminum is such a good conductor that sheet conducts heat away before you can build temp. You may need to find a way to heat dam around a solder area.
shark

Re: Q about sheet metal fabrication and adhesives.

Post by shark »

hy roland I would make it out of galvanized sheet metal then you could easly solder it with propane torch probly easy to get made at sheet metal fab shop. after bending your pieces treat the parts to be soldered with muractic acid just brush alittle bit on then your flux then heat and solder. Galvinized will be alot cheaper than aluminum probly eas'er to bend you might could find tin cans big enough or something like a dog water pan and use that for end caps or a cake pan might work.wedge your seems tight withwood blocks or something to give you a good tight seem to solder . I'd like to see your drums sounds neat a friend of mind makes drums some sound real good. shark [mark barnes] music city usa
PatBearss
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Joined: Wed May 14, 2003 11:33 am
Location: Traverse City, Michigan

Re: Q about sheet metal fabrication and adhesives.

Post by PatBearss »

It might be worth the effort to try the adhesive if you don't have access to anyone who can weld the aluminum. As someone else suggested using round cake pans for the ends and rolling your metal rather than bending might work well and it would give you 1"to 2" to glue and maybe add a couple of well placed pop rivets along the top edge. If there are any local welding shops it might be worth a visit. They might be able to roll the metal and weld it for not too much money, maybe they need a drum?:)
bruceg

Re: Q about sheet metal fabrication and adhesives.

Post by bruceg »

If welding was out then I would do the following. Get enough material to make your trough out of a single u-shaped piece with end pieces. Use (borrow or hire) a box brake to make the bends necessary to produce the u shaped trough. Then fabricate end pieces and attach them with pop rivets. Seal the seams with RTV. It could also be done with galvanized steel and the ends soldered on. I would not fool around with trying to solder aluminum. Just my take.
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