Sanding plywood - I'm having a brain cramp!

snipped-for-privacy@gmail.com wrote in news:1160074934.249651.261820 @i3g2000cwc.googlegroups.com:

I'd probably start with ~100. It depends on how rough the surface is to start with, I usually use less than 110 grit to knock down things that are too high.

Puckdropper

If the plywood is reasonably smooth, 220 may be all you'd need. Normally, I'd start with 120 or 180. Yes, that veneer is very thin so take it easy.

Thats an open ended question.

How thick is the vaneer and how much would do you think you need to remove? Are there scratches? Start with an 80, 150, 220. Heck you can do it all with

It's standard plywood, so whatever the veneer is on it. There aren't any scratches to speak of...the more that I think about this, I probably need to just wet it down and run over it with 80 (or maybe even 150) to knock down the grain, then finish with 220. Only 2 sandings...I like that idea. ;-D

Jim

Double the grit number each time, starting at about 120. Finish beyond

Start at 40 grit if you're actually removing timber and shaping things.

snipped-for-privacy@gmail.com wrote: : Hi all:

: I'm having a brain cramp, which forces me to post a dumb question. I'm : building a wine storage cabinet (it's from the September issue of : "Wood"), and most of it is plywood. It tells me to "sand to 220 grit." : Great, I can do that...but, what grit do I start with?

What sort of plywood? if this is furniture grade stuff, it's already sanded at the factory to 120 or 150 grit. I'd actually either not sand it at all, or start at 180 or 220, depending on the finish you plan to use.

: If this wasn't plywood I wouldn't worry, but my fear is if I start too : low, then sand and sand and sand and sand, then I may go through the : veneer...or am I worried about nothing?

Nope. Face veneer on plywood is at best 1/42nd of an inch, and some is now

-- Andy Barss

If you are using cabinet quality veneer plywood, 150 is plenty coarse enough.

Go from 120 to 240??????????

Where did you get that idea?

It is absolutely a valid worry. For most of the furniture grade plywood I have used, starting & finishing with 220 has been adequate. The face layer of veneer on most ply is eally thin, I wouldn't want to even get near it with anything coarser than 180.

If you're not sure it's best to sand a scrap and test with the finish you plan to use.

I agree with Ed. I assume it is hardwood ply? If so, sanding is almost not necessary except for touching up and bringing things together. 220 should be fine

If it has dings and dents in it, like every pice of wood I handle, you can wet those spots and wiat until they are dry before sanding. That will expand them out. Otherwise you may not be able to remove them without sanding through the veneer.

I even dampen scratches on the assumption that there are probably some compressed fibers underneath the torn ones.

Experimenting with scraps of the plywood would give you some idea of how much sanding. I would start with 150 grit then 220.

Mark (sixoneeight) = 618

Scraps? You have scraps? I plan my project to utilize all the wood and buy exactly what I need. Doesn't everyone?

Given that my project are small yep, as a matter of fact I have a load of walnut scraps about the right size for pen blanks. Problem is investing in a pen making setup might be injurious to my health.

Mark (sixoneeight) = 618