SYP benchtop tearout problem....

[Trey Palmer]

Hi,

Newanderthal here, and have been building a bench. Which I've found to be more challenging than it looks, when lacking a bench to start with.

For the top I ripped SYP 2x10's in thirds by hand and face-glued them, then cheated by "scrubbing" both top and bottom with a tailed router on a sled. The result is a serviceable 72x21x2.5 slab.

Now I'm having major trouble finishing the top flattening job by hand. I can usually edge-joint and face-joint pine boards satisfactorily but I'm getting some really ugly tearout with the same two #7 planes on the benchtop.

Of course the grain on the top laminations is not remotely aligned. I would pay more attention to grain now than I did before, but using Borg SYP the options are limited anyway.

I'm going to try to close the mouth more and get the plane irons sharper -- I use sandpaper on glass to 2000-2500 grit and sometimes get what seem to me to be decent edges, but was not too happy with them last night. I'm either going to buy a fine stone or some of the really good 3M adhesive-backed strips, or both.

I am thinking that maybe a back bevel might help. I would not mind an excuse to buy a Hock plane iron, and then put a 15* back bevel on the old one. Do y'all think that's worth trying?

I'd prefer not to resort to sanding! :D

[David Weaver]

back bevel it or tolerate the tearout.

If you buy cutting boards, and you try to plane them to thickness them, you'll find the same thing.

A back bevel will be a LOT of work (you'll see what I mean when you get your first continuous full length shavings), but you can limit it somewhat by using a good straight edge and planing across the grain first and then finishing with through strokes and a back bevel. Get it as flat as you can with the the strokes directly across the grain, and then (my preference, but maybe not necessary), I would do an X pattern to make sure there's no wind and then length-wise through strokes once the X pattern has cut well.

Since you already have it roughly flat, if it's flatter than I think it is, the Xs and the through strokes might be enough. If you have to remove an appreciable amount somewhere, then check with the straight edge, mark where you need to remove it and go across.

People should always be warned that if you want to be able to hand plane a laminated surface easily, you have to test the boards and mark their grain direction before you laminate them.

[Brent Ring]

Or find someone with a big belt sander and pay them to sand it flat. :)

[David Weaver]

That could prove to be tough on irons the next time you want to sand it.

Of course, you could make it flat enough with the belt sander with the crossing pattern use the belt sander every time. I've never had to plane my bench. If it gets dirty, I run a card scraper over it or an ROS. I don't mind if I bung up the edge of a card scraper if the ROS leaves some behind.

If it was new and fresh and had the chance of moving, I'd want to be able to plane it though.

wait..I've got an idea. Pay someone with a 24" helical head jointer to run it :p

[David Weaver]

By the way, 15 degrees is probably a good place to start. It should mitigate tearout at that quite a bit, and if it doesn't you can step it up.

You have the option to tune a chipbreaker and set it up very very close to the edge, too (like less far from the edge than the thickness of a sheet of office paper for the final smoothing), but the effect will be the same if you back bevel and it might take less time and tinkering and be more straightforward to go right to the back bevel.

One last item - if you're fighting tearout, make the mouth as tight as you can get it and still feed on whatever plane you're using. It'll save you final smoothing strokes.

[Jim Koepke]

Trey,

Your profile does not show your location. If you are near here I know of a shop with a large planer and sander that may be willing to do the work. Since you are using SYP it is likely you are across the country.

jtk

[Harlan Barnhart]

I would live with it for a year or so without a finish and then try again. It will eventually need to be flattened again anyway. From my experience SYP from building lumber is not dry enough to plane properly.

[Trey Palmer]

Wow, thanks for the many quick and helpful posts!

Jim, I'm in downtown Atlanta.

David, it's pretty close to flat. I just need to get rid of the machine marks from the 1" straight router bit. I hand-jointed both the guide rails and sled rails of my jig, and checked that the rails were in plane using crossed twine. Then after flattening the underside I based the top off of it using a marking gauge to ensure it's parallel. There is a "good" side, the underside is knotty and not completely flat because I just shaved off the "high spots".

Harlan, that does make some sense to me. One difficulty is that my bench lives in a den with a finished concrete floor, in a kind of open loft-style house, and the perhaps unreasonable goal is for it to be semi-fine-furniture when not in use.

Towards that end I got lucky last week when a friend happened to ask me if I was interested in buying a workbench base. No usable top, but I already have a top which just barely fits, with some adapting. It's good looking and a lot nicer than what I could have built myself right now.

[Trey Palmer]

Another question:

I now plan for the bench to have an English style front apron, through-bolted to the bench legs and glued to the benchtop. Inevitable top contraction will be allowed for by not having a back apron.

To this end I bought two dry SYP 1x10's (not construction lumber) which I planned to face-glue. My thinking is that it's a lot harder to find a clean 2x10, and if done with opposing cupping forces the two boards will be more stable than a single 2x10. Do y'all think that's the case?

Thanks!

[Jim Koepke]

My thought would be to look for something like a 4X6 or 4X8 for holdfasts.

I am not sure what the best way for the grain direction would be.

jtk

[Trey Palmer]

Thanks for the help!

I ground a 15* back bevel on my smoothing plane iron and was able to smooth out the machine marks with very little tearout. And the few little splinters that did happen are, I suspect, more due to poor technique.

"Tearout" is not really an adequate description for what was happening with 45* irons. More like "gouging huge canyons."

But, that's near the back edge. And there's little point in trying for perfection in a pine benchtop that is gonna dent up regardless.

BTW Harlan, forgot to mention that I bought the wood in July so hopefully that will help a little with stability.