[Splinter]

It didnt really seem that humid today, but I had a crazy problem with layers in the plywood swelling. I'm using 3/4" A-1 veneer core maple ply which has to get wrapped with hardwood so I can route an ogee on it...

About 15 minutes or so after the plywood is cut, every other layer in the core swells enough to feel with your finger.. Hold the solid maple strip against the plywood edge, and you can see a 1/64" gap...

So do you think these swollen ply's will squish down when I glue and clamp on the solid maple strips? I'd hate to have to run every edge over the jointer to smooth it up just before glue-up...

MDF core was not an option for this project.

 

[genecarp]

Strange for that to happen with a quality plywood, i am thinking a defective board/ adhesive, etc...G

 

[neolitic]

Did you just drag it out
of a conditioned building
and into the great outdoors?
Maybe you need to let it acclimate?

 

[Splinter]

Good thought, but nope.. It's been sitting in my shop for 2 days, and the warehouse I buy from is not air conditioned either.

 

[Leo G]

Doesn't matter all that much. Cut it, put glue on it and clamp the solid on the plywood edge. Even if it is the humidity when you apply the glue (I assume yellow) there is water in the glue that will swell the wood also. After the glue is dry everythign should be locked up. If you can't clamp it out you really have an odd problem.

Poplar core or Aspen?

 

[Splinter]

It's greenish, I'm guessing Poplar core... My big concern is the joint between ply and solid.. I dont want that thin black line... I've edged their rotary cut veneer plenty of times without any issue.. This is the first time I'm using their plain sliced maple veneer... It might be a different manufacturer...

I guess we'll see in the morning when I get it together in clamps.

 

[Leo G]

With the grain you shouldn't have a problem. Against the grain you will see the black line. Really can't stop it from happening. Just make sure you use a lighter colored glue. Don't use TB III as it is darker in color.

 

[Gus Dering]

Is it a domestic ply or China / potato chip ply?

I had a huge problem with China ply several years ago

 

[Leo G]

USA, Canada, European. That is all I buy. If it don't have the stamp, take it away.

 

[Gus Dering]

USA, Canada, European. That is all I buy. If it don't have the stamp, take it away.

Me too. Once is enough

I do think the Chinese will get their act together some day but they will get it worked out on someone else's dime

 

[Leo G]

If they stopped putting their waste byproducts in their merchandise, maybe the glues would hold the plys together. You hear a lot of complaints over on Woodworkertalk about metal chips and weird things being found in the borg Chinese plywoods. De-laminating plys, sprung boards, cutting strips that don't stay straight or flat, etc. Never had to deal with it.

 

[rbsremodeling]

It didnt really seem that humid today, but I had a crazy problem with layers in the plywood swelling. I'm using 3/4" A-1 veneer core maple ply which has to get wrapped with hardwood so I can route an ogee on it...

About 15 minutes or so after the plywood is cut, every other layer in the core swells enough to feel with your finger.. Hold the solid maple strip against the plywood edge, and you can see a 1/64" gap...

So do you think these swollen ply's will squish down when I glue and clamp on the solid maple strips? I'd hate to have to run every edge over the jointer to smooth it up just before glue-up...

MDF core was not an option for this project.

where the hell is 1/64" on the tape measure:laughing: cripes you finish, furniture, cabinet maker guys

 

[Leo G]

1/64" is a big gap. Even .01" is kinda big. When your normal work is done to the 32nd, 1/64" counts. It shows in the finish.

So I suppose you skip every other line on the tape, eh? :laughing:

 

[rbsremodeling]

1/64" is a big gap. Even .01" is kinda big. When your normal work is done to the 32nd, 1/64" counts. It shows in the finish.

So I suppose you skip every other line on the tape, eh? :laughing:

When your cutting what?

 

[basswood]

It didnt really seem that humid today, but I had a crazy problem with layers in the plywood swelling. I'm using 3/4" A-1 veneer core maple ply which has to get wrapped with hardwood so I can route an ogee on it...

About 15 minutes or so after the plywood is cut, every other layer in the core swells enough to feel with your finger.. Hold the solid maple strip against the plywood edge, and you can see a 1/64" gap...

So do you think these swollen ply's will squish down when I glue and clamp on the solid maple strips? I'd hate to have to run every edge over the jointer to smooth it up just before glue-up...

MDF core was not an option for this project.

Here is something designed to solve the very problem you are encountering:

http://www.collinstool.com/base.php?page=collins_ply_prep.htm

 

[Splinter]

Bass, Thanks, I've seen those before.... If this is still a problem today, I might go that route... It's domestic ply... Well, probably Canada, but my supplier doesnt stock anything Chinese. I have seen junk in the domestic stuff though. First time I bought from them, they walked me through the warehouse and bragged about how it's all USA made, the best you can get, blah blah blah. I get back to the shop, see the Made in Canada stamp, and cut through thin pieces of metal 4 times in 2 sheets.

where the hell is 1/64" on the tape measure

:laughing: :laughing:

 

[basswood]

What you are describing is not uncommon, even with good plywood, in humid conditions. If the stuff is staying relatively flat, no worries.

You can just use a good bearing-guided, flush trimming bit, if you don't want to wait for the bit from Collins.

Someday I want to get A/C for my shop... you know, so the wood is comfortable in there.:whistling

 

[PA woodbutcher]

I've been starting a fire in my shop once or twice a week for the past couple of months just trying to keep the moisture out. We've only had like 15 rain free days since the middle to end of April.....tough year to be a painter or roofer here in the northeast.

 

[Splinter]

I ran a sanding block with some 120 down the edge of the ply before glue-up, and threw a few extra clamps on it... No Problem-o.

 

[Leo G]

Told ya. :cool2:


Glad to hear it.:thumbsup: