Really bad warping

[stevekendal]

Not been in my radio shed lately and its been getting a bit damp (but not wet) in there. Just noticed that two nice little american sets have suffered really bad warping to the tops which is beyond my usual glue and clamp treatment. These are much too good to scrap so any suggestions please for rectification. Drying etc for best results? Steve.

[stevekendal]

Well,it looks like I'm on my own here, so I,ve brought them indoors into a warm, dry room. Just look how bad!
http://i167.photobucket.com/albums/u...l/PB240049.jpg

http://i167.photobucket.com/albums/u...l/PB240048.jpg

Fingers crossed now. If they dont dry staight, I may have to park my mini on top of them. Steve.

[Radio_Dave]

Hi Steve,

I've really no idea what you can do with these. I can only suggest that you try to glue and clamp them up before they dry out.

David

[geofy]

Would a steam iron work, with a cloth to press the wood down and then glue and clamp it.

Geof

[stevekendal]

Not for such a bad case. I've now put it out in the garage with about 30k on a board bearing down it and it doesnt feel a thing Problem is, on the worst one the top panel has sprung up about 10mm over just 3 inches. Maybe I should re-soak the wood and crush it with a car bottle jack between the house wall and the garage wall adjacent. crrunchhhhhhh whoops

[Station X]

Could you steam it? The problem will be getting a big enough "steam generator". Perhaps an oil drum with water in the bottom and a gas ring or blow torch underneath. You could suspend the panel in it.

Some wood goes soft as anything when steamed and can then be easily bent, or in your case unbent.

[Mark the Mender]

Steve, fom my dim memory of woodworking, the panel would need to be wet, then clamped with a big G clamp from top to bottom of the cabinet, with some wood between the clamp and cabinet, then brought in to dry. The panel SHOULD then dry out in the right place. The clamp would probably have to be adjusted ie tightened daily until the right shape is obtained.

good luck with it old bean! keep us informed

cheers Mark

[geofy]

Originally Posted by Station X

Could you steam it?
Some wood goes soft as anything when steamed and can then be easily bent, or in your case unbent.

I did sugest a steam iron but a more suitable device might be one of the little kitchen type steam cleaners that have a nozzle to direct the steam. Steam it while applying weight until it bends and then hold it in place.

g

[stevekendal]

Well chaps. Think I'm going to have to bite the bullet here and buy/scrounge a pair of sash clamps. The curled tops are just as solid as they ever were, so I think I need to remove the chassis and stand the cabs upside down in cold water, just and so submerging the top panels. Then clamping and waiting. Funny how just the Yankie sets were affected. Better buy British! Steve.

[Ian B]

It looks as though the cabinets are made of solid wood rather than ply. Ply is much more stable with changing humidity, that's why it's used (cost also comes into it of course!).
Probably the varnish or laquer on the outside has prevented the wood absorbing as much moisture as on the underside. Keeping pressure on it while it dries out often works, but it takes days or even weeks for it all to stabilise.
Good luck,
Ian Blackbourn

[Hunts smoothing bomb]

This is quite bad, try and get the cabinet fixed and I would suggest permanent use of a dehumidifier in your shack, I use one 24/7 and would not be without it. If that's how the cabinet has suffered what about the transformers, laminations etc?

Cheers

[stevekendal]

Nope, its ply allright and the layers are starting to part.

[stevekendal]

I just got the loan of a set of massive sash cramps, courtesy of a kind freecycler. My plan is to wet the wood first. Any thoughts on how long to soak the top panel? Steve.

[Panrock]

This is a very difficult problem and I don't know of a real solution. Water caused distortion of the cabinet HERE This wasn't as bad as in your case but I never really cured it. Eventually I simply concealed the damage by filling the crack between the mating panels. Another case of warpage I once encountered was in one door on a Bush television console cabinet. Despite wetting, steaming, and heavy weights, this was slightly improved but never properly cured.

Maybe wetting and weights left applied over months (or years!) would work better... I just don't know.

Good luck,

Steve

[FRANK.C]

Hi Steve
I had a radio with a badly warped top. The whole cabinet was dissembled though which made it easier to straighten. Thread here.

I straightened it by wetting the concave side only and laying some weights on top. The idea being that the water will swell the wood on the concave side only, and help to straighten it. It took nearly a week in my case. You would need to keep a close eye on it as if you leave it too long it will warp in the opposite direction.

Frank

[stevekendal]

Well I already soaked the panel and have eased it halfway back with the aid of the cramps. Will leave it a day or two then crank up the tension a bit. Think the reason why only these two sets were affected is that the panels concerned are blockboard, as opposed to the more usual ply. Steve.

[stevekendal]

Well I was hoping to have some good news by now but alas, no. The wetting and clamping of the sprung edge just made the other end start to lift. (see-saw) , so undaunted, I clamped that edge also and left it in hope. No chance, the side started to bow out under all that pressure and when I released the clamps, back to square one. This seems to leave two distinct options now. 1. Completely remove the top and run over it with a steamroller, or 2. fill in the horrendous 10mm gap and pretend its a rare "art Deco" variant Steve.

[FRANK.C]

Hi Steve
Sorry to hear it hasn't worked.
I would think it has warp upward because the unpainted inside of the panel has soaked up moisture causing the inside to expand where the painted outside hasn't. Wetting the panel on the inside may have made it worse.

I think the most likely thing to work is to remove the panel. Strip the paint from the top and then wet the top only while applying pressure. I know it's drastic but it's the only way I can see it straightening

Frank

[stevekendal]

Well It has all dried out now and I have removed the top panel. Once again however, I was too hasty and its not even blockboard, but a lump of solid timber exactly half an inch thick, with a veneer of walnut on the top surface and a laminate on the bottom with the grain opposed. Strange thing is that this piece is in three distinct shades. It has been suggested to me to make deep saw cuts on the underside and then re-glue it before replacing the laminate, but I dont have a circular saw. Maybe if I remove the top veneer, wet that side and clamp. Bearing in mind that would be just a lump of solid timber then, bending at right angles to the grain, might it work? Steve.

[Radio_Dave]

Hi Steve,

If you can successfully remove the veneer, I'd chuck the wonky bit of wood, replace it with a nice, new, piece of plywood and stick the veneer to that.