Thank you Jose!!

Post by **GlennW** » Mon Mar 01, 2010 6:46 pm

I am making a tool that requires two pieces of A2 tool steel 1" long and .6875" dia, heat treated and tempered to 60RC and then ground.

The key is that I did not want center drll holes in the ends and I don't yet own a Centerless Grinder.

I have been mulling this over occasionally and the light came on yesterday when I remembered a tip from Jose that he gave for holding small parts on his mill table.

I cleaned the parts and Super Glued a stub to them, then chucked up the part in the lathe and center drilled the stub.

I then stuck a MT4 to JT drill chuck arbor in the work head of my OD grinder and faced off the arbor with the wheel to get it perfectly flat and square. I then simply Super Glued the part to the arbor and quickly centered it with the tail stock.

Ground it to .6875 and just broke it off of the arbor and then broke off the stub with the center in it! Problem solved, and a ground part with no centers drilled in it.

Thanks Jose!

Great tip!!!

Jose Rivera · Post by **Jose Rivera** » Tue Mar 02, 2010 12:09 am

Glenn, thanks for nothing

That crazy glue comes in handy at times if one is careful and not trust it 100%

I've done some stuff that it could not be easily done unless glued to a substrate.

Acetone will remove any glue left on the part/substrate.
I normally heated until it lets go (About 150*F), someone here at chaski also mentioned that freezing it also will cause it to release.

Post by **GlennW** » Tue Mar 02, 2010 8:17 am

Jose Rivera wrote:That crazy glue comes in handy at times if one is careful and not trust it 100%.

You will find that a thin sheet of paper between the surfaces as a blotter for the glue works wonders!

TomB · Post by **TomB** » Tue Mar 02, 2010 8:46 am

Jose mantioned:

Acetone will remove any glue left on the part/substrate.
I normally heated until it lets go (About 150*F), someone here at chaski also mentioned that freezing it also will cause it to release.

I'm not sure freezing has an effect. I knocked my ski patrol name tag off the little metal strip last year and hooked it back on with "Super Glue". Its on the outside of my jacket and its been below 0 F a number of times since. The name tag has stayed attached.

Tom

DICKEYBIRD · Post by **DICKEYBIRD** » Tue Mar 02, 2010 9:56 am

Man that's a trick to remember; thanks!

Quick note on super glue: acetone's a pretty good solvent for cured CA glue, nitromethane's a lot better. That's what "superglue remover" is.

I'm lucky, I still have a quart of the good stuff from the good ol' days before NHRA watered it down with 10% methanol for the top fuelers. I was using it to mix my own model aircraft fuel....back before this machining obsession took over my hobby time!

ps: Glen, you ought'a put that trick in the shop made tools thread over on the other forum. That's a good'un!.

Post by **GlennW** » Tue Mar 02, 2010 10:00 am

DICKEYBIRD wrote:ps: Glen, you ought'a put that trick in the shop made tools thread over on the other forum. That's a good'un!.

Wasn't my idea....

I just adapted someone else's idea to my application!

DICKEYBIRD · Post by **DICKEYBIRD** » Tue Mar 02, 2010 10:55 am

Just give Jose credit like you did here and I'll bet he won't be mad at'cha. That's really a good trick that needs to get spread around.

I think G. Bulliss said that VP was going to publish a book with some of the tips posted on the thread (with the authors' permission). You and Jose can add the huge royalties to your retirement funds.

Jose Rivera · Post by **Jose Rivera** » Tue Mar 02, 2010 3:18 pm

Hey, I did not invented this use for glue ... I got it from another machinist and just shared it

Jose Rivera · Post by **Jose Rivera** » Sun Mar 07, 2010 6:16 am

This is a sample of how helpful crazy glue can be.

The disk is 1.25" dia. by .080" think.

No clamping, no marking, full circle to indicate, no hassles.

There was a counter-bore after this picture.

The substrate is just a piece of scrap Plexiglas.

tornitore45 · Post by **tornitore45** » Sun Mar 07, 2010 2:42 pm

While on this subject...
What is a safe time fro superglue to cure at max strenght?

What for Locktite?

I know different for each formulation, but a ball park safe time for someone not in a hurry that does not mind wait a little more than necessary.

thedieter · Post by **thedieter** » Sun Mar 07, 2010 5:38 pm

I was smurfing around on the watchmakers posts on "You Tube" and ran across one that was sticking thin discs on the end of a rod to machine the thickness and diameter of a balance wheel.

He was using a small burner to heat what I think may be rosin to stick the part to the rod.

I want to research this further as I think that it may be safer than Super Glue which I think is weak in shear strength (sensitive to shock).

Best regards, Jack

PixMan · Post by **PixMan** » Mon Mar 08, 2010 9:45 am

When I was making ceramic (SiAlON) intake & exhaust valves years ago, we did a very similar thing to get the prototypes ground to size. We used a Loctite product that I believe is still in production: Loctite Speedbonder 324 and Primer 7075. It's an acrylic adhesive.

Grinding very hard (>90Hb) ceramics with resinoid bond diamond wheels can exert some very high forces. In some cases, the valve stems finished at 6mm (.2362"), so the contact patch of the steel "center" was about 5.5mm in diameter. The steel was just over 1/2" long, to allow clearnce for the wheel to come off the workpiece at the end of the stroke.

The Speedbonder 324 held up in an amazing way. As long as we didn't let too much heat get to it, we could do both rough and finish grind ops without remounting. These steel tips were turned and pre-drilled with the center hole.

As the need for higher productivity came on, things changed and we started drilling a center spot in a slightly longer stem, glue in a steel ball, center drill that, and grind even more aggressively. After finishing diameters, we'd cutoff the excess stem length and discard it with the one-time-use drilled ball in it.

Back to the original prototype method, I couldn't believe how strong the bond was with the 324. It can have the same shear strength while filling gaps up to .060" (1.5mm). I bought a bottle of of the 324 and spray can of the Primer 7075 through MSC for home use, and still use it today for all kinds of applications. I find it to be far more versatile and dependable than cyanoacrylate (Super Glue) because of it's gap-filling capability. It needs at least .1mm (.004") thickness to work well.

Fixture strength in 30 minutes, 50% of full strength in 1 hour, 85% in 6 hours and 100% of full strength in 24 hours. No, it's not the fastest but it's solvent resistant and strong as an ox. It does not like heat, as that's how you separate the parts when you want to. But we had no problems with grinding as long as the coolant was on (and we never ground ceramics dry anyhow.)

https://tds.us.henkel.com//NA/UT/HNAUTT ... 324-EN.pdf