Stanley #39 Question

[John Erhardt]

Hi again. I was wondering if I should buy a few new Lie-Niels... no, wait. Sorry. That's not my question.

I really have a quick question for any Stanley #39 users.

So I'm actually in the market for a #39 3/4, though I've had someone offer to sell me a #39 3/8. Trouble is, I don't see much use for a 3/8-in. dado, as it's not a size I can see myself needing often (to my knowledge, that's never stopped someone from buying an otherwise perfectly good vintage plane...).

My gut says that I can cut a 3/4-in. dado by measuring out the dado's location and setting up some kind of straight edge to run the plane against that splits the dado into two equal halves. Then I run the 3/8-in plane down the exposed half and cut to depth before moving the fence over 3/8 of an inch and planing the other half. 3/8 + 3/8 = 6/8 = 3/4.

But will this work, or am I missing an obvious limitation of the tool? I'm not sure if there are nickers on both sides of the body, but this method would mean one nicker isn't nicking anything. And I'd be willing to bet that I'd tip the plane when I planed the second half of the dado, since it would be unsupported on one side. My current method of cutting a dado is to scribe the shoulders, chisel out the waste, and use a router plane to clean up the bottom. So I'm basically not looking for the most efficient way to cut one, but an acceptable one.

So I suspect I should just wait for an affordable #39 3/4 to pop up, but the 1/4 and 3/8 are just so much more common that I'm hoping I can improvise. I guess I'm just wondering if this is more trouble than it's worth, or if I can easily cut 3/4-in. dadoes with an undersized plane and minimal cursing.

Thanks,

J

[Steve Rozmiarek]

John, the only limitation that I can see is that the handle on the 39 is low, especially when you get down to the depth you need, and any type of fence you use, is probably going to interfere with your knuckles. Could probably use a different grip and make it work... Why not just use a 3/8" dado, and rabbet the ends of whatever goes into the dado? Or you could just buy the 3/4".

There are nickers on both sides of the plane BTW.

[Pedro Reyes]

John,

I am going to second Steve's suggestion. To me the ideal dado plane is around 3/8". A dado is usually for joining cross and straight grain so wood movement is an issue. Here I am assuming you intend to use a 3/4" thick board to go into your dado, so if you use a 3/4" dado the fit will change with the seasons. I like to rabbet the ends of my boards instead (e.g. shleves) to go into a dado about 1/2 or 1/3 of total thickness. This not only reduces the thickness which will move inside a dado, but also hides those lines, and you get strength from the resulting shoulders (like a long M&T).

Do you need a better excuse to get that tool ;).

/p

[John Erhardt]

Thanks for the response, guys. It sounds like I've underestimated the usefulness of a 3/8-in. dado, so that's reason enough to pull the trigger on this.

But Pedro, you're correct. I have a few bookcases looming (just bought a house, have to fill it with furniture) and I was planning on 3/4-in. cherry or red oak. Probably cherry. Anyway, very simple design based on something my father made for me a long time ago, and that used 3/8-in. deep 3/4-in. dadoes to hold the shelves in place. I admit I have a pretty rudimentary understanding of wood movement, so if the better structural idea is to do as both you and Steve suggested, I'm there.

J