Help in flattening table top WITHOUT belt sander.

Re: Help in flattening table top WITHOUT belt sand

fmutchler@adelphia.net

>Alan, it sounds like your #4 is too short to flatten the top. The #4 is following the existing cup condition because it is not long enough to bridge the gap, so to speak.

Do you have a #7 or #8? The #4 can be used to smooth the top after you get it flat with a jointer length plane. If you don't have a longer plane you could make the #4 do the job but it will take a lot of extra work.

Re: Help in flattening table top WITHOUT belt sand

Alan Tolchinsky

>Hi FM, Yes I do have a #7 but not in good shape; it needs work but maybe it's time to do that. :) What you say makes sense to me though. I'll try my 7 once it's up to par. Thanks Alan

Re: Help in flattening table top WITHOUT belt sand

Dave (Arlington, VA)

>Hi Alan -

Sorry to hear about your table top flattening troubles.

I have a question or two for you: first, is there any twist to the table top or are you sure that your only problem is with it being cupped? That is, have you used winding sticks on it, and if so, what was the verdict?

Second, I wonder if you are using the wrong hand plane. You could do it with a smoother, but a jack or a fore might be better.... for the flattening part of this effort (not the smoothing - which, as you know, comes later).

Third, flattening a table like this involves a repetative process that includes taking some shavings and then checking for flattness, taking some more shavings and checking again for flattness and so on... working your way (relatively slowly - at least for me - and) methodically up the table top. I usally mark the high parts with a pencil and then go at those for a few strokes... and then re-check. I have a feeling that when one is better at this than I am the process goes quite a bit faster.

Anyway, best wishes on the tabletop.

Regards -

Dave

Re: Help in flattening table top WITHOUT belt sand

James Watriss

>Ditto what everyone else said about using a jack or jointer to get it roughly level. Smoothing planes are more for smoothing the surface when you already have it flat. A few things to think about:

-The new-fangled low angle wonder planes aren't the only ones with adjustable throats. They're easier to adjust, to be sure, but you can close up the mouth on your 4, as well. Loosen the frog, use the screw under the adjusting wheel to slide it forward, and close it up really tight. Figured woods are a pain in the neck to plane, and the tighter the mouth you have on that plane, the better. You'll only be able to pass fine shavings, but at that stage, that's the idea anyway. That'll help prevent you getting more tear-out. You could try to close the mouth up some on the jointer, too, it might help you keep from getting more tear-out that way.

-I know it sounds cock-eyed, but when you go to flatten with the jointer, you may want to try planing cross-grain, or at an angle to the grain direction, while holding the plane at an angle. You still want to pay attention to which way the grain is rising, but it'll help you keep the wood from splitting ahead of the edge that way.

-Keep those blades SHARP. I know, you know that already. Make sure they're stropped, too, and if it starts feeling dull, go back to the stone. Maple can get hairy with dull blades, particularly when it's figured.

-When you go to tune up your 7, make sure it's dead flat. I've had bad times when I've used jointers that were bowed slightly. I'd adjust until I'd get a fine shaving, but when I hit a patch of hairy grain, the blade would dig in, the plane body would flex, the edge would dive, and then the plane would bounce back and leave an unholy gouged-up surface.

Re: Help in flattening table top WITHOUT belt sand

Alan Tolchinsky

>Hi Dave, Thanks for the info. No I'm not using winding sticks as I thought since the glue up went pretty well(flat) that twist should have been minimal. Mistake here?

I'll check with winding sticks just to cover my bases and go from there. I'll figure it out one of these days. :) Thanks again. Alan

Re: Help in flattening table top WITHOUT belt sand

Alan Tolchinsky

>James that's a lot of great info. I'm going to close up the mouth as you suggested and go with a bigger plane. I did wet towel the wood but saw minimal improvement.

I was able to sand out most of the tear out with my orbital sander but sanding is what I'm trying to avoid. I'd like to just use 220 grit after planing or no sanding at all. That's my goal and you've helped me to achieve that. Thanks. Alan

Re: Help in flattening table top WITHOUT belt sand

William Duffield, on the Cohansey

>Alan, you also have to check that your bench top, under the planed table top, is flat. The table top will move with the weight of you and the plane and the force of the planing. Any place the benchtop is low, the table top will just move out of the way under the long plane. The table top will only get thinner under the high spots on the bench. If you keep checking the progress of your work and if you know where the bench top is out of flat, you can correct for this, but you can't just blindly plane the surface and hope the plane and the bench will work automatically.

Re: Help in flattening table top WITHOUT belt sand

James Watriss

>Yeesh... yeah, random orbitals are great, but spot-sanding with electricity does make for an uneven surface.

Another thing I should mention... invest in a good 24" straight edge, if you don't have one already. Some sort of machinists' rule is ideal. Starrett is obviously one of the most expensive, but I've seen some relatively decent chinese-made ones on ebay lately. Just remember to handle them gently and respectfully. You're not paying that much so you can measure inches. You're paying that much so you can measure thousandths and millionths, by looking for light under what should be a very straight edge. As it was told to me, places like Starrett use dark rooms to check things for flat and square. Supposedly, in such a room, with a small light on the other side of whatever you're checking, the smallest space that light will shine through and still be visible to the naked eye is something like millionths of an inch. But that's only viable if it's a truly straight edge.

When you check your board, (or the sole of your plane) use the longest thing possible. Obviously check for flat along the length and width, but remember to do both diagonals, too, at intervals across the board. That'll help you get a sense of whether or not it's wound, as well as where the high spots are. After a while, you can set for a reasonably fine shaving and be able to anticipate about where the plane will grab. That is, if you can visualize what the topography's like, based on what you find with your straightedge. I'm kind of a freak sometimes, so sometimes the things I say end up being "just me."

Wet planing is nice, but I think for some things I still prefer cross-grain. Wetting things down makes the fibers more pliant, that's for sure, but if you're worried about splitting, going cross grain means there won't be much of a continuous shaving to begin with, so there's nothing to split ahead of the cut. Closing that mouth up will help a lot, too. Before they used chip breakers, old school planes used the front of the mouth to help break the shaving. The front of the mouth held the shaving down, and the blade cut the shaving and broke it against that forward part of the mouth simultaneously. When there's not enough space for the shaving to arch up and slide up the back of the blade, the only other alternative is to break off at the front of the mouth.

Clark and Williams still do this with their smoothers... I heard Larry Williams say once that he thought chip breakers caused more problems than they solved. Some of their wooden smoothers are made to take shavings that are thousanths of an inch thick, without a chip breaker.

Of course, old wooden planes needed to get tuned up from time to time, and eventually the mouth got bigger after a while. I've got one in front of me here that has at least 1/4" between the edge and the front of the mouth. So chip breakers were another way to fight tear-out, given that problem.

The less room a shaving has to get up into your plane, the less your plane will be able to tear it out. If you're doing curly or birdseye, the less of a bump or curl that can get up into the plane, the better.

BUT, that's smoothing work, and not necessarily relevant in flattening. A bit of a smaller mouth on the jointer should help with that maple though.

Re: Help in flattening table top WITHOUT belt sand

les winter

>Hi

I suggest you refrain from further sanding until you are completely done planing and scraping. The abrasive bits left in the wood will dull the life out of your blades.

good luck!

Les

Re: Help in flattening table top WITHOUT belt sand

Greg Sloop, Portland Oregon

>While closing the mouth of the plane may help a bit, the total cut angle is the most important to prevent tear-out.

Perhaps a back bevel is in order. In case you don't know what a back bevel is, I'll explain. On a bevel down plane, the bevel is behind the cutting edge - trailing it, so to speak.

To raise the effective cutting angle, you either have to raise the bedding angle, or if you can't do that, but a honed bevel on the front of the iron as well as the back.

If your frog is a 45 degree frog, then probably raise the bevel angle to around 50-55 degrees, or if really wild grain, to 60-65. So, a bevel on the front of say 10 degrees might help a lot. (Any more than that will make the jointer a *lot* harder to push too. Use the smallest cut angle you can and still have acceptable surface finish.)

With the jointer, you don't have to prevent *all* tear out, just the worst stuff, so you won't have to take too much material off with the smoother after jointing. It's a lot more work having to remove a lot of material with the smoother, and you also risk losing some of the "flat-ness" too, perhaps reintoducing some of the problems you just got rid of with the jointer.

Cheers,

Greg

Once it is flat, try a card scraper...

Jonathan Kaplan (OR)

>All the above suggestions re: getting the board flat are excellent, and I've nothing much to add to them.

But once the board is flat, if you have small areas of tear-out or plane tracks, etc., and want to put off sanding a bit longer (or avoid it all together), I would suggest moving to a card-scraper. They are after all very inexpensive, and good instructions on getting a burr are available on-line in several places, and they do very well with wild figure hard-woods, etc.

Just an idea I thought I'd toss out.

Best,

jk