Primus jointer

[bugbear]

More Steve Knight stuff
http://woodcentral.com.ldh0138.uslec.ne ... read=32912

if your getting a hour out of the belt something is wrong. either your not doing much or it is more worn then you know. Your lucky to get 10 minutes out of a good belt if you work aggressivly. what is happening is the belt wears in the middle more then the sides and the ends. so it ends up cutting faster in those places and you get a rounded sole.

changing the grit often is critical to flattening soles.

And
http://woodcentral.com.ldh0138.uslec.ne ... ?read=6801

Bugbears file method is the way to go to get the bulk off. it is really hard to remove much metal with a belt sander accuratly. only if you stick with fresh belts and nothing below about 180 grit. 220 and it is hard to goof up but you go through some belts.

it is pretty hard to remove much material with lapping and not screw it up.

He likes me!

Don't forget that Steve Knight is often flattening wooden plane soles, although he earnt his metal plane flattening skills when he produced some infills.

BugBear

 

[kygaloot]

See David Welter's description of Krenovian planemaking at College ot the Redwooods (step 9). I imagine that they have made a few there.

http://www.crfinefurniture.com/1pages/s ... plane.html

Course, they are just following what Krenov himself promotes in <i>The Fine Art of Cabinetmaking</i> , not that Mr. Krenov is known for being particular about things.

 

[MikeW]

Is this a new thing? here's his report of 2004...

That could be before or after the last time I was actually in his shop. I don't know. Could be I was smokin' crack the last time I was in the shop, I'm not sure. I do not remember it being that thick nor made from granite.

Don't forget that Steve Knight is often flattening wooden plane soles, although he earnt his metal plane flattening skills when he produced some infills.

I thought the Primus under discussion was a wood plane. My apologies if it is not.

Look BB, are you actually saying an abrasive fixed to a reasonably flat surface will not work for flattening the OP's Primus *wood* plane? Or are you just jerkin' the chain?

No matter how flat this--or any other wood-bodied plane gets today, it will move next season, and the next, and the next until eventually it needs another serious flattening.

What exactly did the lowly 18th century cabinet maker in the depths of Devon do when he needed to flatten his wood planes each year and or season? Run down the the machine shop? Nah, he used another plane. One which he hoped was flatter than the one he was working on. And he accepted slight amounts of tear out. Or broken boxing.

Heck, he may have used a rasp or file if he had one. Ever see a rasp or file from that period? Trust me, MDF coupled with an abrasive fixed to it is much flatter than many I have seen from the 18th and 19th centuries.

Take care, Mike

 

[Alf]

What exactly did the lowly 18th century cabinet maker in the depths of Devon do when he needed to flatten his wood planes each year and or season?

Nipped along to Axminster and bought the latest one just shipped over from the colonies? :-k :lol:

Cheers, Alf

 

[bugbear]

Look BB, are you actually saying an abrasive fixed to a reasonably flat surface will not work for flattening the OP's Primus *wood* plane? Or are you just jerkin' the chain?

Long ago I (tried to) flatten the sole of a skew rebate , by rubbing on sandpaper on glass.

The sole is 8x1 1/2.

I recently had cause to revisit the tuning of this plane, and checked against a surface plate.

It was quite badly convex.

I have NEVER succeeded in getting the rub-on-abrasive approach to make things decently flat.

Check out the quotes and experience from other people on my web page for third party corroboration, especially the Spiers smoother story.

I continue to recommend an experiment on scrap wood before working on a valuable LV soled plane, checking the result against a trust worthy reference.

BugBear

 

[Philly]

BB
I have lapped a few planes using the sandpaper method. The secret is to stop when you get close-there is a point you reach when it is as flat as you can get and then it goes concave. A reference surface is essential to approach the "flattest" you can get-if not, going slow is my recommendation. Take off the worst and try it out. Take a few strokes more and test again.
Another thing to remember is this-the expected use of the tool. You don't need a jack plane to be as flat as a smoother :idea:
Hope this helps
Philly

 

[JesseM]

Yes it is a woodie!

So I had a shot at it last night. I was debating on what to use for the flat surface. So I picked a scrap of 3/4 ply checked with a straightedge, and looked for twist. It seemed good enough. So I attached some 220 grit sandpaper with double sided tape. I was gonna trying the scraper, but I have misplaced it.

The first couple swipes showed me that it was hollow around the mouth, and the heel. I took a sharpie marker and rubbed it on the toe, heel, and around the mouth, and worked from there. I definitely got rid of the hollows around the mouth and heel. As to how much better it works, I will find out this weekend.

BTW lignum vitae dust sucks. Its green and it irritates the throat. I'll remember the next time to wear a mask.

 

[kygaloot]

Check out the quotes and experience from other people on my web page for third party corroboration, especially the Spiers smoother story.

You have a strong argument with regard to sandpaper lapping the soles of metal planes.

However, my experience with wooden planes tells me that uneven wearing of the sandpaper and the resulting effects are insignificant. I don't think I've ever spent over 15 minutes truing the sole of a wooden plane, including those that I have patched. The fact that Steve Knight can use the same sandaper on his lapping plate for months proves the point.

 

[bugbear]

I've checked with Steve Knight. He used to only get 15 wooden planes flattened on a 6" wide AlZi planer belt before replacing it; after this the differential blunting of the abrasive prevented accuaracy. For a one-off plane (e.g.a Primus jointer) this should be OK.

The reason Steve bought the huge granite plate was to AVOID edges. Proportionally, there's much less edge on a large surface.

He now uses single PSA AlZi sheets the size of his plate (24x36) in 120 grit, and he normally gets around 6 weeks use.

Fairly extreme tactic for the rest of us though

BugBear

 

[kygaloot]

He now uses single PSA AlZi sheets the size of his plate (24x36) in 120 grit, and he normally gets around 6 weeks use.

Thanks for investigating further, Bugbear.