Plane Flattening ?

[Bill Miltner]

I have a #7C Record Jointer that I need to flatten the sole. (Yes, I flatten the sole on all my bench planes) Usually I use silicon carbide sandpaper wet on a granite block, but the jointer is just too long for my 12" granite piece.

I have an extra cast iron wing for my table saw that I intend to use for this process. But I have a question as far as the best process however. Would it be best to just adhere the sandpaper to the CI top and do it dry, or wet the paper and deal with the possible rust issues? Either way I have clean-up issues, either the adhesive or the water on the CI.

[Danny Thompson]

Adhere the wet/dry sandpaper. As long as you clean up immediately, you should have no problem with rust.

For a plane this long, be sure to use a long strip of sandpaper (i.e., the entire sole should be in contact with sandpaper at all times to ensure even wear.) Long sanding belts are a good option.

[Jim Koepke]

I just recently bought some 4-1/2 inch rolls of PSA sandpaper from Supergrit.com for lapping plane soles.

Worked fine for me using it dry. Every 10 strokes or so a brush was used to clear away the dust. A vacuum would likely also work well. The grits used were 80, 120 and 220 if my memory is working.

jim

[jerry nazard]

3M makes a product to place on stair treads that has an adhesive backing. It's really just heavy duty 60 - 80 grit sandpaper. My hardware store sells it cut to length. I got excellent results by sticking it on my jointer bed and keeping it clean (swarf free) with my shop-vac and a brush. After using it to flatten planes, you can reuse it on your stairs!

[Jim Koepke]

3M makes a product to place on stair treads that has an adhesive backing. It's really just heavy duty 60 - 80 grit sandpaper. My hardware store sells it cut to length. I got excellent results by sticking it on my jointer bed and keeping it clean (swarf free) with my shop-vac and a brush. After using it to flatten planes, you can reuse it on your stairs!

How wide and how long are the 3M strips?

For a #7, 3 inches may not be wide enough. My setup was using about 3 feet of abrasive surface.

jim

[jerry nazard]

Jim,

The product is "3M Safety Walk" and it is 4" wide. My hardware store stocks it on a roll and it is sold to length. I got the best results by doing what you suggested in a previous post: keeping it as free from swarf as possible.

Here's my evening gloat: Picked up a type 11 #5 the other day for $4.25. After a few hours work it is rust free and so beautiful! Did not come with a knob so I fitted it with a bun. Looks funny but it is quite comfortable and is intended to be a user. Four dollars and twenty five cents! When I was a kid that was a LOT of money!

Best!

-Jerry

[Bill Miltner]

How about the grit on the sanding strips, I have always used silicon carbide, but how about Aluminum Oxide or even Alumina Zirconia?

[Jim Koepke]

Here's my evening gloat: Picked up a type 11 #5 the other day for $4.25. After a few hours work it is rust free and so beautiful! Did not come with a knob so I fitted it with a bun. Looks funny but it is quite comfortable and is intended to be a user. Four dollars and twenty five cents! When I was a kid that was a LOT of money!

Best!

-Jerry

Now that $4.25 is a lot of plane! Nice gloat, I would have picked it up too, even though there are already two #5s (type 9 & 11) in my shop.

How about the grit on the sanding strips, I have always used silicon carbide, but how about Aluminum Oxide or even Alumina Zirconia?

My most recent rolls are Aluminum Oxide and Zirconia. I like the Aluminum Oxide better. It seemed to hold its cutting edge longer than the Zirconia. That could be because the AO was 80 Grit and the Zirc was 150.
The 80 seemed like it was good enough to give a smooth surface on the planes sole. There was still a scratch pattern but not that bad. Usually, I am not much for plane sole lapping, but a couple of my planes needed it. They work better after the lapping, so that is what matters.

Was talking to my wife today about getting a big hunk of granite or other material to make a lapping bench. Not sure if it will happen.

jim

[philip marcou]

I have a #7C Record Jointer that I need to flatten the sole. (Yes, I flatten the sole on all my bench planes) Usually I use silicon carbide sandpaper wet on a granite block, but the jointer is just too long for my 12" granite piece.

I have an extra cast iron wing for my table saw that I intend to use for this process. But I have a question as far as the best process however. Would it be best to just adhere the sandpaper to the CI top and do it dry, or wet the paper and deal with the possible rust issues? Either way I have clean-up issues, either the adhesive or the water on the CI.

I suggest you use a sanding belt, no glue, find a way of clamping it tight across the table top - and - use kerosene on it. This will speed up the process, which is painful enough as it is, and there will be no problem with water damage. The abrasive belt/paper/cloth or whatever is not going to cut well for long anyway so anything which enhances cutting action is welcome, in my view

[george wilson]

How accurate is your table saw top? If it is Blanchard ground,showing circular grinding marks,it may not be more than .003" flat. If it is a cheap saw,I'd be careful of its accuracy. Do you have a real accurate straight edge? I don't mean an aluminum one.

Zirconia (blue belts) are much better than aluminum oxide. The finer grit referred to above made the zirconia seem less sharp. I don't even think about using ALO on my knife grinding belts. They cost a bit more,but cut a LOT faster,and last a lot longer.

[Danny Burns]

This might be a good time to skip the hassle and head to the machinists shop.

[Sean Hughto]

Have you tried the plane? Why do you think you need to mess with the sole at all?

[Bill Miltner]

To answer several questions posed to me, The table saw wing is from a General cabinet saw and is quite flat, <.002" measured with a starrett 24" straightedge. And no offense intended, but if the plane cut the way it should I would not be flattening it.

Thanks for the comments, I may well use a 36" Zirconia belt and clamp it to the table saw wing and see how that goes first. I am in no rush.

[Sean Hughto]

" (Yes, I flatten the sole on all my bench planes) "

This aside from your original post suggested that perhaps you just did it as a matter of course because you assumed it was necessary.

Whatever.

[Jim Koepke]

T
Thanks for the comments, I may well use a 36" Zirconia belt and clamp it to the table saw wing and see how that goes first. I am in no rush.

Having used other belts and sheets, with clamping and spray adhesives. It came to me to buy some PSA rolls. It was money well spent, in my opinion. Easy to put down to stay down and peel up left very little residue to clean up. It worked very well.

jim