Source for modern hollow and round molding plane irons?

[Patrick Chase]

In fact, I used to work at the UCSD machine shop, which is in your general area. I could email you their contact info if you need it.

When were you there?

I was an AMES undergrad from 89-93. I worked for and later with Dave Tribolet for a good chunk of my HP career (he recruited me straight out of 156A/B)

[Steve Voigt]

When were you there?

I was an AMES undergrad from 89-93. I worked for and later with Dave Tribolet for a good chunk of my HP career (he recruited me straight out of 156A/B)

After you, from about 94-2000. I was a grad student in the music department, and I kept afloat by working part time (and full time in the summers) in the machine shop. I stayed at the shop for a couple years after I finished my coursework, because WTF else are you going to do with a PhD in composition?

Dave's name sounds very familiar. I'm wondering if he worked with a guy named John; we built these cannons for them with 4" barrels to shoot stuff through concrete. Almost as cool as the 13-ton "shaker tables" we built that were used to simulate earthquakes…that place was intense. Anyway, good to know you were there!

[Patrick Chase]

After you, from about 94-2000. I was a grad student in the music department, and I kept afloat by working part time (and full time in the summers) in the machine shop. I stayed at the shop for a couple years after I finished my coursework, because WTF else are you going to do with a PhD in composition?


Dave's name sounds very familiar. I'm wondering if he worked with a guy named John; we built these cannons for them with 4" barrels to shoot stuff through concrete.

Dave is an industry adjunct and taught AMES-156A/B (now MAE-156A/B), the upper-division design course for mechanical engineers. AMES-156B in particular involved design projects, and a lot of those went through the machine shop. IIRC in 1994 they built an electric cart, which they may have donated back to the shop.

EDIT: Was Steven Shick (sp?) still in the music department when you went there? I'd been a cellist for a long time before college, but took his "intro to rock" as an easy way to kill a humanities reqt. I recall being pleasantly surprised at how he covered it.

Almost as cool as the 13-ton "shaker tables" we built that were used to simulate earthquakes…that place was intense. Anyway, good to know you were there!

Ah yes, the Casa de Hegemier (Powell Structural Systems Lab).

[Patrick Chase]

Or you could try https://www.onlinemetals.com/merchan...2&top_cat=1354 for the same size O-1 at a little more than half the price. Online Metals is a a division of ThyssenKrupp Materials North America, so not some fly-by-night source. Lots of other choices there, too, so you may want to look around a bit once you get there. I've found them a very good outfit to deal with.

Yep, I've done business with Online Metals and they're good.

The price difference is probably because the Starrett one that I linked is precision ground (Amazon doesn't say Starrett, but that's what it is). You don't need that in this case, so the Onlline Metals one is clearly a better bet. Thanks for the correction.

[Patrick Chase]

Good Lord! $114? If you send them to me, I'll do six blades for free. You pay shipping both ways. That's to harden and temper. O1 can temper in my oven to Rockwell C 62 and down; for these blades I'd suggest you might find RC 58 about right from an ease of sharpening standpoint, although O1 isn't that difficult to sharpen at any hardness.

Shouldn't that be Rc62 and *up*? Or are you saying that your oven doesn't go below 450F? :-)

To temper full-hard O1 down to Rc58 you'd need to heat it to 580F, give or take depending on whose chart you're using.

[Mike Allen1010]

Thanks Steve and Dave for the advice. I guess I just need to bite the bullet and "take the plunge" of heat treating. I'm hoping I can get a map torch and some fireplace bricks at the local BORG. If not, I'll be back looking for sources.

Thanks, Mike

[James Waldron]

[snip]

Stirring the part around is generally frowned upon, because it can cause warping. Best to go straight up and down, fairly slowly.

I agree, but since the OP is worried about working at high temp, I wanted to encourage him to go above and beyond. Hence the bit about after the sizzle stop before stirring, which should be down to or at least very near the required 800 degrees. At that point, stirring can't do harm (in my experience, YMMV).

After about 15 seconds, maybe 30 at most for a large bench plane iron, you're done. There is no point in leaving it in for 3 or 4 minutes.

Again I agree but there is a point to 3 or 4 minutes for the OP: it will get the temp down to the point where he's very unlikely to burn himself. Since that is his concern, I thought it might be good to let him get a bit more sophisticated after he's attained a bit of self-confidence in the process. And again, I don't see a potential for harm.

The purpose of heat treating is to take the steel from around 1500° to around 800° in the required time interval. For O1, that time interval is about 5 seconds; for W1 it's less than a second. At that cooling rate, the part is surely cool enough to handle in less than 30 seconds.

The cooling rate slows as the termperature drops. AT 30 seconds, the OP may find the piece hot enough to be worrisome. 3-4 minutes is enough overkill - with no real harm done - to make sure he's comfortable.

Decarb can only happen at or near the critical temperature, around 1400°. There is no point in wrapping in foil when you are tempering.
If you stick small molding plane irons in an oven by themselves, they will overheat. Even if the thermometer reads accurately, there will be temperature spikes when the heating element or flame comes on. To prevent this, put something on the bottom rack to absorb heat and act as a shield, and put the blades on the top rack. A heavy cast iron pan, is good; even better is to fill it with something like a roast. I'm totally serious. The planemaker Bill Carter said "put it in the oven with the lamb roast" and I thought he was just being cute, but he wasn't. The roast will help a lot to smooth out the temperature fluctuations.
Alternatively, as George has said here many times, an accurate toaster oven is better than a household oven.

Maybe my mentor was using the charcoal as a heat sink. I don't know and he never said. But I've always been a bit suspicious of that arrangement.

But you're quite right, across the board, as usual. Thanks for the review of my post.

Fair winds and following seas,

Jim