Official Luthiers Forum!

On the subject of tooth plane irons....

Yes.. Make your own.... A file won't do the job, but a Dremel cutting wheel is just right for the job...

The trick is to go slow and don't push so you don't draw the temper.... The grooves only need need to be 1/16" to 1/8" deep at the sharpened end - they don't need to go the whole length of the iron...

The other thing I found about Toothed irons is that the quality isn't nearly as critical as with standard irons... I find the $3.00 Hardware store irons work just fine for conversion into a toother.

BUT... I like to have 1 plane set up for toothing and another set up for smoothing.... as your toothing plane needs to have a wide, fat mouth opening to handle all the chips...

Thanks

Cumpiano strongly recommends that a beginner like me uses a toothed plane - so you think I should too?

I was not going to, as a user here suggests he prefers not to use a toothed plane, however he was probably more experienced than me

I have a 4 1/2, I would like a 3 for toothing

I could get a 5 1/2 though - what do you think? I have above average sized hands

You might just find a toothing blade in a Stanley type plane a bit more troublesome than you think. I know that they sell blades for the purpose (I have one) but there is usually an easier option than the toothed blade IME - like planing across the grain.
In fact come to think of it a toothed blade might be better as a single iron in a woodie, less chance of the thing clogging. I'll have to try it. With double irons they back the chipbreaker right off and some even 'seal' the chipbreaker with some sort of gun mastic.

I would prefer to practice my sharpening before buying another plane or a good quality blade
unless i put a cheaper blade in my record without widening the mouth of the plane
don't want to ruin quality items

P.S.
my record iron's blade edge is not at 90 degrees with the side edge - not sure how to fix this without resorting to grinding (don't have a grinder yet)

also...

can I ask what kind of dehumidifier and/or air conditioner you use Michael? it's RH 45% in my house right now, last night is was 70 - 80%

that's assuming my new western caliber IV's factory calibration is correct

It's an EBAC. Cost about £200. I don't use it much, only when I need to glue the parts that need controlled humidity. Waste of good electrons otherwise. Maximum I can get it to drop is about 8%, too many leaks in the room. I get by with it though, you just have to plan ahead.
You can square your blade with a honing guide and coarse wet/dry paper or a coarse Oil stone.

so when you approach your gluing task, you put the EBAC on for a week and then commence the gluing task on the seventh day?

Don't be silly. We use very thin wood that reacts fairly quickly to humidity changes. In fact my wooden hygrometer lags behind my digital hygrometer by about 30 minutes or so.
I give it 4 or 5 hours with the wood out in the open i.e. not stored flat.

I see, that's very useful information for me. So after you have, for example, glued the braces on - the dehumidifier can be switched off once the glue is dry?

If this is the case, I will buy an air conditioning system that also acts as a dehumidifier

Yes, once the glue is dry. The workshop will have to be returned to the same humidity when assembling the Guitar, gluing bridges on etc.

I have unfortunately ruined my soundboard spruce

while trying to shoot the plates, I could not get them to pass the candling test and now I have planed them so much that they are too small to be used for a full sized guitar (dreadnaught or similar sized)

when I plane, I am taking more wood off the middle of the plates than the ends, I can't get my planing to be even

Firstly, it's not ruined. Just wing the lower bout, stealing wood from the 'spare' that is at the side of the upper bout. - just move it down. Make sure you use the exact same upper surface, don't flip it over. Mark it in pencil before you even cut it out.
The amount of wood that you are removing when jointing is so fine that it is less than the thickness of a tissue paper, I mean the tissue when you split it. The blade should be sharp, shave hair easily without 'grabbing' them.
You also need to move the boards up and down against each other to find out where the hollows and humps are. If the hollow is on one of the boards, that hollow will move up as you slowly slide one board against the other. That tells you which board the hollow is on. If that hollow disappears it suggests that the hollow is on the other board.

thanks Michael you have helped me out many times now

I will give my plane a more thorough sharpening and give it another try, not feeling very confident after this blip but I will eventually learn how to do this correctly

fingers crossed

On the toothing plane...
Yes - I find them very, very useful when thicknessing... I like to set them up to take a nice, deep cut - and they will do so without the tearout you might end up with on a straight iron... You can then clean up the ribs left behind with a standard smoother type plane without issue....

On spruce - it doesn't really matter too much... but on Backs and Sides - especially the harder woods... It really does make a big difference... It's certainly worth the extra $3.00 for the cheapie iron....

on plane sizes... I wouldn't waste a fancy 4 1/2 or 5 1/2 - I would just dig up a plain 'ole #4 or #5 out of the bin and use it... I do most of my toothing with a standard #5 stanley that also wears a corrugated sole...

Thanks

John

On your soundboard joints coming out hollowed out in the center and tall on the ends....

That is typically mostly Technique related....

What's happening is that there is more pressure on the cutter in the center and less at the ends... hence the deeper cut in the center....

2 things:
1 is where you are jigging it. Typically - clamping in the center = hollowed out center when planing...

Even having a lump on the backside of the soundboard where it's resting against the ledge of a shooting board will do this...

Change your jigging/clamping to the ends for a couple passes - then re-check.

If you had clamped the thing on the ends for the entire process - you would probably end up with a proud center and shallow ends....

2 is your hand pressure through the cut... This is one of the reasons it's so important to take the absolute minimum depth cut you can make.... BUT... you are putting more pressure on the center of the cut than the ends....

Work on perhaps gliding the plane into and out of the cut - keeping a very steady speed and very light pressure.... Try to think about uniform thickness shavings....

BUT.. I like to use a precision ground straight edge to check my jointing progress... At the very beginning - I will lay the straight edge against the top half and ONLY knock down the obvious high spots.. and only work those high spots... As you get closer to right - 1 part length shaving will mess up the candling... Then - switch to a full length shaving... but pull 1 shaving then candle... Stop when it seems like you are going in circles.... That's when it's back to "Technique-ville" again...

Thanks

I think you must realize that toothing blades are used for two different tasks. The fine toothing irons sold by the better tool houses like Lee Valley & Lie Nielsen are intended for planing wild grain in wood such as walnut burls and plainsawn rosewood. In this case, the toothed blade will remove a sparse but even layer of wood fibers that can then be smoothed with a regular blade.

Cumpiano/Natelson suggests using a blade scored with triangular saw file for marking every other pass as an aid to seeing where you have passed before. Then you can go back with a regular iron for a second pass, avoiding planing the same path twice, which makes it possible to evenly thickness a wide plate. It also will reduce the tendency to tear out.

There's no reason to buy an expensive fine toothed blade just to make a scratch pattern! Good luck.

I have been working on sharpening my iron, one problem I noticed was the back of the iron is flat, but the front of the iron is not. After trying to fix this by hand and having a tough time along with the bevel losing shape, I ordered a bench grinder and a coarse grit water stone by norton.

My board is similar to the one in the video, but it does not taper

I will take a look at the sharpening video, thanks Todd

Thanks Filippo

My bench grinder arrived today

It was immediately apparent that a dressing rod is needed, I should be able grind the bevel freehand with the tool rest I think, then I will create the micro bevel on my 240 grit water stone freehand

I searched for quite a while, but did not find any tips or guides on honing plane irons on a bench grinder

Bench grinders: Dangerous things, mainly to the Plane blade but sometimes to the user as well. The only thing I would use one for is to take out bad nicks in a blade otherwise for sharpening they certainly aren't necessary.
A coarse oil stone is good enough. You don't need to get the bevel flat. It doesn't really matter if this is convex. What matters is the angle right at the tip/edge of the blade. That edge or the very tip needs to be done with a fine stone. Either an Arkansas, very fine wet/dry or 6,000/8,000 waterstone. You can strop as well. No need for honing guides. Better to learn without them IMO.
Here's one method. I don't use this method but I'm sure it works.

http://www.youtube.com/watch?v=vvTcReENk9g

I seem to be going round in circles trying to sharpen this plane iron

Tried different methods, grinder, sandpaper, waterstones

In my latest attempt, I got a straight, fairly even bevel, started lapping the back via the rule trick and now the edge is no longer straight

I am now thinking of buying a lie nielson, veritas or hock iron as this 1950's blade is not being taken great care of

What do you want a straight edge for? Why are using the ruler trick.? Stop trying to get even bevels, perfectly straight edges. Just get a sharp edge. That's all that matters. Unless your '50's blade has lost it's temper or seriously pitted there's nothing wrong with it. You'll have exactly the same problem with new blades.

I have done as you said Michael, it seems very sharp now

The spruce was warped last night so I have been straightening it hopefully will get it back on the shooting board by tomorrow

Thanks Michael, I became pedantic about the sharpening process. It will take time for me to learn to sharpen to the standards of experienced luthiers.

I am still trying to flatten my wood without luck

Is it necessary for the plates to be flat for jointing?

Use an old Tormek wet grind wheel when necessary and it really is an excellent tool then a diamond plate, have finished with a Japanese wet stone. After the wet stone blades look really shiny but i'm not convinced they are much sharper than they left the diamond plate. Probably pilot/operator error.

Steve

I managed to get the top to pass candling and the plates are being glued together now

The shavings were less than 0.05mm, the minimum measurement on my calipers

thanks all