Baltic birch warping

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LelandCrooks · #16 Post by **LelandCrooks** » Sun Sep 30, 2007 7:05 am

It's a lot of work, but it can be fixed. Rip through the ply in the center of the warp. Invert one piece so the the warps are opposing each other. Dowels or biscuit joiner, glue the panels together, forcing them to engage. Lots of clamps for holding panels flat and together. It's usually used with expensive lumber to salvage it, or to make a specific grain pattern.

Les Webb · #17 Post by **Les Webb** » Sun Sep 30, 2007 12:37 pm

My dad taught carpentry at a the local Vocational/Techinical school for several years. During that time he took his students out to tear down an old barn that was made of solid oak planks.

The oak planks were straight as a string when they were taken down, but after planing and ripping them down into strips, they only had enough decent oak left to build a standard sized coffee table. Pretty sad as the grain was beautiful.

That was mid 80's and we still have the coffee table at the house. Nearly all the bookshelves, hat racks, bunk beds, coffee tables, gun/rod cases at my parent's house were hand built by my father when he taught at school.

Les

brodave2 · #18 Post by **brodave2** » Fri Oct 05, 2007 11:33 am

I just posted last week with the same problem with auraco plywood. I started my assembly this morning, and the warpage was not a problem. If you cut the panels straight and square they will straighten and square each other up. use a 3" x3" clamping plank like the instructions say, and just line everything up, bend it back into place, line it up with your lines, all that then put in the screws. I was shocked at how quickly and easily things went together. Be really careful with that Lowe's blondewood. The outer layer is VERY thin and not attached well. I have built two things with blondewood, and on both the outer layer delaminated. It does lay flat, but it does come apart, and it DOES NOT have exterior glue. I have auraco laying on the ground for a year out in the weather that is still solid

Fri Oct 05, 2007 11:43 am

brodave2 wrote:. I have built two things with blondewood, and on both the outer layer delaminated. It does lay flat, but it does come apart, and it DOES NOT have exterior glue.

Blondewood is useless for cabs. Plans specifically state not to use plywood with thin veneers.

brodave2 · #20 Post by **brodave2** » Fri Oct 05, 2007 3:14 pm

Plans specifically state not to use plywood with thin veneers.

I've used 3/4" birch that has a thin veneer in cabinet building for many years. I never had any trouble with it, but I never used it as in your designs where the glue was the main source of panel adhesion. I always used plenty of nails or screws and the glue was secondary. Obviously, in your designs, that would not be an option, so such plywood would not be a good choice. The reason I say this is to cast a negative light on the blondewood. The thin veneer delaminates out in the middle of the sheet. It can't stand any humidity at all. I have a case I built the lid out of blondewood. It has a big bubble in the middle where the veneer raised up. The 3/4" birch I've used does not do that. I've had it rot into the dirt outside and the veneer was still intact. That blondewood is some sorry crap.

Art Coates · #21 Post by **Art Coates** » Fri Oct 05, 2007 8:16 pm

vlad335 wrote:Since I never saw anyone post any mention of BB warping after being ripped

"flat" when used in reference to plywood is a relative term (as Marko pointed out) ...and well, mine warps too. A full sheet is usually stacked along with other sheets, flat, so that it us held "flat." When you cut the sheet in smaller pieces, the internal stresses in the full sheet have been relieved. BB also seems to me to be more prone to showing effects of temp/humidity than other woods.

If its a piece you'd really like to have straight, dampen it pretty good and put some weights on it until it dries - preferably in a warm, dry area. After all, thats what made the original sheet "flat."

Otherwise, glue & screw the piece as if it were flat, bending it into place, and it'll be fine.

loaferz · #22 Post by **loaferz** » Sun Oct 07, 2007 11:09 pm

using 3/4" Arauco 7 ply, sturdiest stuff ever. Great stuff from lowes, plus, seems to be holding up against this houston humidity better than my old 3/8"" 3 ply shiz wood.

vlad335 · #23 Post by **vlad335** » Tue Oct 09, 2007 12:52 pm

Well.. I just bought some more BB from the same vendor, ripped it down this am and its fine. I'm told the problem I originally described probably happens in 1 out of 100 sheets.

Luck of the draw I guess...

Frankenspeakers · #24 Post by **Frankenspeakers** » Tue Oct 09, 2007 4:01 pm

vlad335 wrote:Well.. I just bought some more BB from the same vendor, ripped it down this am and its fine. I'm told the problem I originally described probably happens in 1 out of 100 sheets.

Luck of the draw I guess...

Heh, heh, heh...
If I had a dollar for every time I have been told by a service rep for several Injection molding machine brands "well I have been a service tech for (fill in the blank) years and I have never seen one of those to fail... yeah right! just be aware that you may have been getting the 'shine on' treatment. However, if its a reputable shop it might really be true, but I have found that to be rather a rare occurrance...

(Must have been another graduate of the 'Joe Isuzu' school of customer service)

Tue Oct 09, 2007 4:05 pm

loaferz wrote:using 3/4" Arauco 7 ply, sturdiest stuff ever. Great stuff from lowes, plus, seems to be holding up against this houston humidity better than my old 3/8"" 3 ply shiz wood.

Did you not read the plans where it says to use 5 ply 1/2" plywood? I hope that's not the only instruction you missed.

loaferz · #26 Post by **loaferz** » Tue Oct 09, 2007 6:56 pm

i know what the plans say, but at the time, lowes was out of 1/2 inch,

i know its probably overkill, but i really like how much more sturdier these cabs feel. they may weigh more, but they feel solid. never have to worry about splitting the wood with screws and i think the extra 1/4 inch should hold the sound in better.

of course this screws up some of the dimensions, but all you really have to do is increase the width of the base and top by 1/2 inch, everything else seems to fit perfectly with orig specs.