As I learn hand planes...next question.

[®smpr_fi_mac®]

I've figured out a good system for getting my stock plane blades sharp.  It'll work for now, and once I burn through the stones (Norton water stones), I'll replace them with diamond plates.  Why?  Because I'm sick of flattening them!




Anyway, I'm actually learning to enjoy sharpening them (and chisels).  It's neat to see the shavings they produce, the sound of the blade slicing, and the feel of it.  I can't yet get those whisper-thin shavings, but I'm getting there, and I think my cap irons might help with that.  Looking at the contact surface, I can see that none of them are perfectly flat or straight across.  How should I work on that surface to get it to fit tighter?  I know it needs to be ground down, but I don't want to attack it without knowing a method that will produce a good surface.  I have a grinder, but is that the right tool to use?  If you know of a YouTube video that shows the process, please link it!  Paul Sellers is a favorite of mine, but I haven't yet seen him fixing a cap iron.

Thanks a bunch!

[Admiral]

No grinder, unless you have a Tormek, there is a way to do that with the jig, but you have to be careful. I'd suggest you start with a file, you have to eyeball the right angle, get it straightened out, then go to the stones, and a few swipes, then mate it to the back of the iron and look for light, wash, repeat rinse until you get it tuned properly. Then take some high grit sandpaper 1k is good, and polish off the burr you put on the top of the chipbreaker, and Bob's your uncle.

[®smpr_fi_mac®]

Sweet. Thanks.

I wouldn't have thought of that alone.

[bandit571]

Some other "hints" along the way:

Have had a few cap irons come through the Rehab Shop....that when you lay them on the bench...they rock side to side.   I find where the high spot is, face it up.  A nail set can then be used to tap ( with a hammer) a few times to get rid of the spot.  

If you look at the "gap" between the back of the iron and the cap iron...note where the gap is.   In the middle?   Hammer the high spot down, On each corner?   Flip the cap over and drive the high spot down.   Much easier to work on the cap when the edge is straight.

Grinding:   I try for a "knife edge".   Where it is thinner out where the cap rests on the iron.   When you tighten things down, the thin edge will flex just enough for a tight seal.  

Instead of a grinder....I set up a belt sander, upside  down.   I turn the sander on, and lock it.   I can then hold the cap iron along the side of the moving belt.   The curved hump hangs just on the edge of the platen.  With the rest tilted down to get the angle for the knife edge.  

Once that is done, I can polish the hump part to remove any burrs. 

Clear as Mekong Mud?

[JimReed@Tallahassee]

I guess I have been lucky because most of my Stanley cap irons have been straight and never needed drastic help. ALL of them, however, needed a little touch up on the end. After I have finished honing the blade, I get a piece of used paper, put it on the edge of the sharpening tile, and bring the tile to the edge of the bench. Then I hold the cap iron at a low angle and give it six or eight back and forth swipes. Rinse and repeat. It is quick and always results in an iron that sits flat and mates well with the flattened back of the iron. I apply the cap iron and expose only about 1/16" or less of the blade. Then I use a big screwdriver to tighten the irons together. REALLY tight. Like lug nut tight. 

When the cap iron is close to the edge and the blade assembly is tight, cutting is usually outstanding. Really thin shavings rarely try to get stuck between the cap iron and the blade. And I find that a sharp blade that is well bedded rarely chatters. Another trick to wispy shavings is to skew the plane 5-10 degrees--especially when you begin the cut.

Good luck making fluffy shavings.

[Timberwolf]

Sweet.  Thanks.

I wouldn't have thought of that alone.

........................
I hold the cap iron in a position that puts a slight bevel on the iron in such a way that the front edge of the cap iron is the only part that touches the stone....IOW, the top part of the cap iron is lower than the flat of the stone..This almost guarantees that the front of the cap iron mates perfectly with the blade...
   Sometimes on old planes, I have found that the cap does not press very hard against the blade when tightened because it has become "stacked" from being clamped so long against the blade....I correct that by clamping the cap in a bench vise and giving it a rap with a soft hammer so as to put a little more "spring" in the iron..That also helps stiffen the blade to reduce "chattering'.

Edit...After posting this, I see that Bandit is achieving the same result using a little different method. I guess it pays to read the entire thread...

[Admiral]

Sometimes on old planes, I have found that the cap does not press very hard against the blade when tightened because it has become "stacked" from being clamped so long against the blade....I correct that by clamping the cap in a bench vise and giving it a rap with a soft hammer so as to put a little more "spring" in the iron..That also helps stiffen the blade to reduce "chattering'.

+1.  I mount it in the vice between the screw hole and the yoke hole, and use the rubber mallet, lightly and not too many times or you deform the breaker. Also, if the mating part  of the breaker is deformed just a little bit on the corner edges (which I find to be the case about a third of the time), just mount the breaker in the vice on the flat before the curve, then light raps on the corners.  Tuning a chipbreaker is one of the more important parts of preparing a vintage plane for a new working life, I do it on all the planes I work on.

[Strokes77]

There is a LOT of wisdom in these threads.

I appreciate you men sharing what works for you.

[®smpr_fi_mac®]

Thanks, gents! I'll look at these things when I next get a chance to find my way into the shop.

[Timberwolf]

+1.  I mount it in the vice between the screw hole and the yoke hole, and use the rubber mallet, lightly and not too many times or you deform the breaker. Also, if the mating part  of the breaker is deformed just a little bit on the corner edges (which I find to be the case about a third of the time), just mount the breaker in the vice on the flat before the curve, then light raps on the corners.  Tuning a chipbreaker is one of the more important parts of preparing a vintage plane for a new working life, I do it on all the planes I work on.

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"Tuning a chipbreaker is one of the more important parts of preparing a vintage plane for a new working life, I do it on all the planes I work on."

And you can tell by the photos of Rich's planes in action that he knows what he is talking about !!!!!..Whisper thin shavings!!!!!