I’ve recently built some kitchen cabinets for some friends where I used baltic birch plywood. This is the first time I’ve worked with baltic birch. Might as well experiment on a friend’s project, instead of a family member’s. Right? I’m happy to say it came well and they really like it. To remove table saw marks I did what I normally do and ran it over the jointer a couple times. However, later on I noticed I had small groves in my jointer blades.
Is this a sign of the wrong blade material? I used high-speed steel. Is it a no-no to joint plywood? If it is, how do you remove saw marks?
Thanks,
Dennis
Replies
I think it is likely to experience nicks in jointer knives when running plywood through. I am not sure if it is the glue or the end grain that causes it. I use a block plane and a light hand sanding afterwards. If I’m covering with edge banding I don’t bother.
I don't know if it's a "no-no" or not but, with plywood, you are jointing end grain on every other ply. That and the glues they use may be tough on your jointer blades. I've had similar issues when jointing hard woods like Oak with knots. You may have less issues by using one of the newer helical heads with carbide inserts.
It is the glue. It is abrasive and will nick the HSS blades on the first pass.
agreed. i've seen it on HSS router bits.
I haven't tried them and they aren't cheap but you can also buy carbide knives for a jointer. No idea if they would help or not.
I don't own a jointer machine. As such, when I've needed to smooth an edge on Baltic birch, I've used either a No 4 or 5 hand plane. It worked fine. Maybe I needed to sharpen it a bit sooner than normal but wasn't much of a noticeable difference vs. using my hand tools on hardwood and the blade just sharpened as normal on my stones. Just passing it along as an alternative option.
Thanks for the feedback. The thought that it is ok to joint baltic birch plywood came from this clip. About 3 minutes in he says the jointer blades will be fine after a couple of passes of a sandwich of MDF and plywood. In my case, it only took one pass to put groves in the blades.
https://www.finewoodworking.com/2011/07/01/build-a-super-precise-tablesaw-crosscut-sled
It's the glue as others said. The same thing will happen to laminated hardwood. A table leg of glued up 4/4 oak was my 1st experience. I eventually did the carbide insert head and it's worth every penny. There is a temporary fix until you can sharpen or replace knives. You can offset the knives horizontally so fresh steel from 2 blades goes over where the nick(s) is on the third.
Baltic birch will certainly groove HSS knives but I have found "regular" plywoods don't. In the video he is not using baltic birch, nor does he claim it is. In most cases, I think it would be used as a panel and would be enclosed in a frame so wouldn't need jointing. I like the look of the exposed plies and often use it for drawer sides, in which case I use a round over bit in the router table and sand off any saw marks that might be left.