Grinding Wheel Guard Project

[GlennW]

The foil wrap (high temp stainless steel) is to seal the parts to keep the oxygen away from the surface while at higher temps. The presence of oxygen will cause the surface of the steel to "burn" and become flaky and scaly. The steel still seems to discolor from the heat, as you can see, but it stays relatively clean. Without the wrap, it would have a build up on the surface similar to that of hot rolled steel.

Thanks!

[ctwo]

Thanks Glenn. I'm guessing tin foil is not a good substitute.

I was watching modernblacksmith on youtube anneal some tool holders in a coal burning forge he made and he commented on the scaling if it got too hot. I did not know that would be a problem in a more controlled environment.

That's a nice stove, BTW. My mom has a small kiln for her stained glass work - built from light blocks and a coiled wire heater - with at least 10 years of dust on it. I've been wanting to borrow it to make metal soft and hard again. She won't let me use it, thinking it might get damaged since it's designed for glass...

[GlennW]

The American Sun 4" vise, still coated in Cosmoline, with it's new jaws installed. Interesting vises. Were made in PA and are hardened and ground tool steel, extremely accurate. Basically a screw operated tool makers vise. They made a 3" as well. Now out of business.

One of the new jaws for the Kurt. I'm likin' the new coolant system on the grinder as it sure is a lot more fun grinding A2 now than it was grinding it dry.

The jaw installed with it's new stop as well as retaining the ability to use the little Kurt movable stop. The new stop will go on either end of the jaw. I have it on the right side presently as I have both the vise and the Super Spacer on the table.

There is something nice about using things you made or tinkered with.

[warmstrong1955]

Put another jaw on the barbie eh mate?

Nice Glenn.....

We all like shiny things....


Bill

[buffdan]

Beautiful finish on those items Glenn.
What wheel did you use, and specifically what coolant do you use?
I enjoy all of your projects..

I have a surface grinder in my basement shop and I am achin to use coolant.

Dan

[GlennW]

Hello Dan

I believe it is Castrol Syntilo 9902, but I'll check tomorrow to make sure, as Castrol offers different types.

http://www.castrol.com/liveassets/bp_in ... 06_pds.pdf

I was using a Norton 5SG46I wheel, which may be slightly on the hard side, but I was using an 8" wheel which I spun at 2800 rpm to hopefully help it act just a bit softer. I was trying not to get a real slick finish on the jaws to help with grip, and it seemed to work out about the way I wanted it to. If I had a 46H, I would have used it, but this one actually worked quite well and did quite a bit of work between dressing.

Being new to coolant on a surface grinder, and having little experience on parts of decent size, I'm kinda figuring it out as I go, as it's a bit different (easier) for sure!

Thanks!

[GlennW]

Dan,

It's Syntilo 9930.

http://www.castrol.com/liveassets/bp_in ... o_9930.pdf

[buffdan]

Thanks Glenn.
I'll look into that coolant.
Its really confusing ( at least for me) to pick the "right" coolant for home shop use.
Of course we want no odor, no rust, no bio hazard..

Kind of suprised you didn't use a finer wheel to obtain that nice finish..

Also like your photography.. Nice sharp well exposed photos..
Dan

[GlennW]

I use Castrol water soluable oil in other machines and the Castrol synthetic in the surface grinder and find that they have nearly no odor to them at all. I have used other coolants in the other machines and as soon as you walk in the door you smell them. I have never had the Castrol coolants I use go rancid either.

Thanks!

[Patio]

Glenn I like the work you do. It is always clean looking.
I sure do like the look of a ground finish.

[GlennW]

Thanks, Pat!

One set of Kurt jaws has a small dovetail at the top corner so I dressed a 1/4" wheel to 30 degrees by using the sine chuck and a slide dresser.

Set up the jaw using a 1-2-3 block against the back bar. That's why I like things square. I stuck the block and the jaw on there and ran a DTI along the surface of the jaw parallel to the X axis and it was out .0002" from end to end. A tap with my knuckle and it was good. Makes setups quick. I have five machines with back bars which is why I like matched blocks.

Then ground that little dovetail square and parallel to the rest of the jaw surfaces. It needed very little grinding to clean up.

Now I have a nice sharp little dovetail on each jaw to grab delicate parts with without applying much jaw pressure to hold them. It's a .060" step.

[Harold_V]

I'm guessing tin foil is not a good substitute.

Chuckle! Depends on your objective. If you hope to protect the piece being heat treated, it won't, as you'll quickly go beyond the melting point of aluminum.

I was watching modernblacksmith on youtube anneal some tool holders in a coal burning forge he made and he commented on the scaling if it got too hot. I did not know that would be a problem in a more controlled environment.

Correct. Professional heat-treaters typically use controlled atmosphere furnaces, whereby the material gets discolored, but not oxidized. That's critical, as a prolonged heating cycle burns out carbon, leaving the surface dead soft, incapable of being hardened, even if the underlying material gets hard. That is recognized as being decarbed, and is, in a sense, the reverse of pack carburization, whereby instead of adding carbon to steel, it is removed. It's common for hot rolled alloys to receive a machining process to remove such material.

Harold