Bowed Veneer Panels?

[mttt]

Been 'sperimenting with resawing and veneering. Resawed some 6" wide, 30" long 4/4 Jatoba stock into 1/8" slices. Was flat after the cut. Believe the stock to be dry - but lack a moisture meter.

Edge glued (Titebond) the veneers together to get a 12" wide, 30" long sheet. Then a couple of days later, glued (Titebond Extend) the 1/8" thick veneers to 1/8" thick baltic birch - aiming to end up with a 1/4" thick door in the end.

Both panels bowed up - one much more than the other. Bow is cross grain - across the 12" width for the Jatoba.

When I was experimenting with some 4/4 Maple a week earlier - same sizes, same thicknesses - the bowing also occurred but with the grain - along the

30" length.

I don't recall whether how I oriented the Baltic Birch panels underneath - but was thinking since they're more plywood-ish than not, they should be relativley stable.

Can anyone help me understand (a) what I could have done to prevent the bowing [e.g was the stock too wet; too thin; wrong glue] and (b) what might explain why the Jatoba bowed cross grain and the Maple bowed with grain???

[ Head scratchin'... ] Thank you!

[DarylRos]

Did you glue a backing sheet to the panel? If you didn't it will certainly bow up.

Also, Titebond is not the glue to use for veneers. Eventually it will creep on you. Unibond 800 is better for veneering.

I don't know why they bowed differently. Possibly the way moisture got in the panels, or how the glue dired, don't know. But if you glued a 1/8" veneer sheet, which is fairly thinck for vener onto a 1/8" panel, you will always get bowing. That's why you need to glue the back as well.

[Kim Whitmyre]

From my reading, "Making Traditional English Furniture," the author uses only hide glue, and he applies glue to both sides. He fixes it to the substrate with the glue, hammers it out from the center, and then applies glue to the top surface. He then uses a hot, moist towel (as hot as you can manage to hold) to wipe down the surface, thereby removing excess glue. Of course, you can't do that with titebond. . .

Kim

[Gary]

To reiterate what Daryl said: If you veneer a panel - do the same thing to BOTH sides of the panel. Otherwise you'll have unequal stress on each face of the panel and some sort of bowing, curling, twisting is inevitable. When I veneer I always have some "cheaper" quality veneer handy to do the back sides of panels. Just as long as it's the same relative thickness and I glue it the same way (same glue type) and with same grain orientation. One thing you'll note on plywood - it's almost always made up of an ODD number of sheets of veneers - that's to balance out the stress in the panel. On a side note: Jatoba is pretty cheap around here (less than 4 bucks a foot). Unless it's a highly figured piece of wood and all you're looking for is a 1/4" piece - why not just use solid wood? Veneering and resawing is best saved for rarer woods and figured woods you want to get more out of or do things like bookmatches with.

Gary

[mttt]

Thanks! All part of the learning experience.

S3S 4/4 was $7.50 a BF @ Paxton here in Denver. [ When I saw their Cherry for $9.50 a BF (OK it was 4/4 *wide* stock, but still!) I started to wonder if their prices are going a smidge out'a line. Might be time to try a Steve Wall UPS bundle. ]

Just looking to get in some practice. Am new at this and wanted to practice resawing.

Am glad I'm practicing on more common and cheaper stock - cuz I seem to be screwing it up! :) Thanks again for the lesson.

[Gary]

MTTT, I just bought a bunch of Jatoba at the Paxtons here in KC. Think it was $3.90 a board foot. That's why I commented on using solid wood. Think cherry is around 6 to 6.50 these days (which is why I switched to the Jatoba on my last project). Can't believe they have they much of a price differential between stores even if it is in a different region. Bet you could pick some up cheaper via mail order from somewhere.

Next on my wish list is a decent bandsaw so I can practice on some resawing as well. How did the Jatoba resaw? I enjoyed working with it on a table I built, but the stuff is harder/denser than hell.

Good luck with the practicing!

Gary

[mttt]

Me neither. On my to-do list to hit some of the other dealers in town and compare prices.

Surprisinginly easier than I expected. Given it's Janka rating, I was expecting a real battle. Perhaps if I had a riser block and was trying to resaw 12" wide stock. But it went through with only moderate more (granted subjective) pressure than the maple.

Blade was a Suffolk saw (AS 1/2 inch 3tpi, IIRC) . Had a WoodSlicer but decided to try the Suffolk blade first since I had it tracked and tensioned.

On the table saw, it was only 4/4 stock, but that DeWalt 40 tooth Series 60 blade I picked up for $29 did a wonderful job. The only burns were my fault, pausing to grasp for the push stick.

Thanks - I'm going to need it! ;->