If I wanted to put a 20 to 30 degree bend (not too tight a radius) about 3 inches from each end of a 24" piece of 5ply (which would be about 6" wide), how might I make/procure a press suitable for the operation? -- Snob? Were I a snob, I wouldn't be talking to you.
On Fri, 16 May 2008 16:30:42 +0100, Dave Budd <dave.b...@manchester.ac.ku> said in <MPG.2297b8f94abf2c10989...@news.individual.net>:
>If I wanted to put a 20 to 30 degree bend (not too tight a radius) about >3 inches from each end of a 24" piece of 5ply (which would be about 6" >wide), how might I make/procure a press suitable for the operation?
I usually do this by making a jig, bending some 6mm ply into shape, and laminating two or three lots of 6mm into one large whatnot.
The message <MPG.2297b8f94abf2c10989...@news.individual.net> from Dave Budd <dave.b...@manchester.ac.ku> contains these words:
> how might I make/procure a press suitable for the operation?
Sorry, with ply you don't. You start with veneer and /make/ curved ply.
Well, sort of. There's a bodge - you can kerf several layers of thinner ply - slice /nearly/ through them so they're bendy. Then you can laminate them yourself to molish a thicker ply, but it won't be so strong.
Were you to make your own, you can make a former by whatever means you like and then lay up the veneer (ply will do if it's thin enough) and then shove it in a plastic bag and connect it to the vacuum cleaner. The sharper the curve, the thinner the layers have to be.
-- Skipweasel Eagles may soar, but weasels don't get sucked into jet engines.
The message <eshr24d474ip7uas1g9cqcr167h7r9i...@4ax.com> from Countess-Palatine Blackberry the Perplexed of Divine Intervention.<x{yz}enophi...@hotmail.com> contains these words:
> IRIA "Blending plywood" and wondered why anyone would bother.
Oh, that's 'cos not everyone likes single-source ply. It can be rather too woody, so they either blend it or take it with ice.
-- Skipweasel Eagles may soar, but weasels don't get sucked into jet engines.
<dave.b...@manchester.ac.ku> wrote: >If I wanted to put a 20 to 30 degree bend (not too tight a radius) about >3 inches from each end of a 24" piece of 5ply (which would be about 6" >wide), how might I make/procure a press suitable for the operation?
As has been said elsewhere, you can't bend (modern, epoxy-bonded) plywood, but if this is a very old, very sheddy piece which was bonded with hot hide glue, then you could. Laminating your own ply from veneer and pressing it into shape is pretty k3wl.
Five ply? Five times 0.6mm standard veneers or thick, chunky shuttering ply with gurt big centre plies?
If you only want something about 3mm thick, consider using solid wood because that's pretty easy[58] to bend by hand - all it takes is heat, damp and evenly applied pressure. You could even do it in the kitchen with a pot of boiling water, a saucepan to bend it round and a flat piece of scrap wood to bend it with. Or you could borrow an electric bending iron from my instrument repair workshop, if you want.
If you want to use something fatter, like the shuttering ply , you could bend a fatter piece of solid wood but it's harder work - after all if they bend shafts for pony carts, anything smaller than that must be possible. So here's a bodge instead. With a broad-bladed saw, kerf the area you want to bend with closely-spaced slots through four but _not_ all five of the layers. Use heat and moisture to bend very carefully. Spring the slots open a smidgeon and fill with epoxy. Let the curves spring back into shape, squeezing out the excess epoxy as they do so. Leave until set hard.
Nick
[58]I have been doing it for about forty years and I think I'm getting the hang of it -- real e-mail is nickodell (at) bigfoot (dot) com
> The message <MPG.2297b8f94abf2c10989...@news.individual.net> > from Dave Budd <dave.b...@manchester.ac.ku> contains these words:
> > how might I make/procure a press suitable for the operation?
> Sorry, with ply you don't. You start with veneer and /make/ curved ply.
> Well, sort of. There's a bodge - you can kerf several layers of thinner > ply - slice /nearly/ through them so they're bendy. Then you can > laminate them yourself to molish a thicker ply, but it won't be so > strong.
> Were you to make your own, you can make a former by whatever means you > like and then lay up the veneer (ply will do if it's thin enough) and > then shove it in a plastic bag and connect it to the vacuum cleaner. The > sharper the curve, the thinner the layers have to be.
Bum. I'd read on t'web that you can steam and bend ply, but now you lot tell me that's only with the old-style stuff. Solid wood's not really any good for this - it's a skateboard deck. The bending was for the kicktails. I have a 31" which is too big for Jack, and I just bought a 17", which is too small, really (and way too rigid). So I was thinking of making a 24" myself. But if I have to bond veneers into my own plywood, it's getting a bit too much, really.
Is it the same sort of resin as in fibreglass? -- teh internets is populated by eggshells armed with hammers
Guy King wrote: > The message <MPG.2297b8f94abf2c10989...@news.individual.net> > from Dave Budd <dave.b...@manchester.ac.ku> contains these words:
>> how might I make/procure a press suitable for the operation?
> Sorry, with ply you don't. You start with veneer and /make/ curved ply.
That's not true. I have bent plywood many times. It's very easy to do. Here's my procedure:
1. Ohl a nice piece of plywood for a QVL project you have in mind. 2. Store it in the shed, propped up at abou a 60-70degree angle to the wall. 3. Forget about it. The thicker the piece of ply the longer you have to forget about it. 5 Stack up other stuff against it - bicycles, garden loungers, lawnmowers, etc. The heavier the better. 4. Assemble enough tuits for the project. Take a day off jbex. Discover that the ply has sagged and now has a nice curve all across it.
The message <MPG.22988c62657375eb98a...@News.individual.net> from Carlton Miniott <daveb...@ukmisc.org.uk> contains these words:
> But if I have to bond veneers into my own plywood, it's getting a bit > too much, really.
It's surprisingly easy. Carve a mould with a surform out of a slab of pine - the finish doesn't have to be anything special. Lay polythene over it to stop the first layer sticking. Lay up several crossed layers of ply that's thin enough to bend to what you want, with suitable glue and vacuum-pack. It's really a lot easier than you think.
-- Skipweasel Eagles may soar, but weasels don't get sucked into jet engines.
Costing the net hundreds if not thousands of dollars, Guy King said:
> The message <MPG.22988c62657375eb98a...@News.individual.net> > from Carlton Miniott <daveb...@ukmisc.org.uk> contains these words:
> > But if I have to bond veneers into my own plywood, it's getting a bit > > too much, really.
> It's surprisingly easy. Carve a mould with a surform out of a slab of > pine - the finish doesn't have to be anything special. Lay polythene > over it to stop the first layer sticking. > Lay up several crossed layers of ply that's thin enough to bend to what > you want, with suitable glue and vacuum-pack. It's really a lot easier > than you think.
Since you know what you're doing, fancy going into the 24" skateboard deck market? I'll take 2... -- teh internets is populated by eggshells armed with hammers
