Mandrels again and a bribe - Page 2

blong2001 · #31 2010-09-07, 5:26am

Someone here told me that to temper the mandrels torch them until they are red and then drop them in to cold water.

Anyone know which is the better way to do it?

Jenn L'Rhe · #32 2010-09-07, 7:33am

Good question Bethany.

I've never heard of the torch way. They would get hotter, but not an even heat. Wonder how hot they need to get? How do you hold them?

Torch tempering would take FOREVER to do 40-50 mandrels. Using my normal scheduling techniques, I wouldn't get to empty the dishwasher, sweep, vacuum or start a load of laundry....the things I usually do while ramping up. LOL

I do know that my way does work....if I forget to take my mandrels downstairs when I turn the kiln on and just dip them while the concentrator warms up, I can tell when I take the beads off. The mandrels are softer and bend MUCH easier.

PittsGlass · #33 2010-09-09, 2:39pm

Quote:

Originally Posted by gemsinbloom

I am not doing this but to be honest, I don't really have the time to mess around like that but I appreciate the suggestion.

You'd only have to do this with a batch of mandrels once every so many uses, not every time. You can also put them in a hot kiln, wait for them to get heat soaked all the way through, and pull them out with pliers and dunk. I do this with 3/32 mandrels when I notice bends when removing beads.

gemsinbloom · #34 2010-09-09, 2:43pm

An update from me. I purchased some 316L 3/32 steel rods and a bolt cutter today. I made a kiln full of beads and I am quite pleased. I find it much easier to make beads on these larger mandrels. Last night I created two beads on 2 3/32's I found in my studio. They come off the mandrel easily, easier and a dream to clean as well. When creating pendants with the larger holes, I filled the 20 gauge silver wire with seed beads, the length of the bead and zero wobbling!

If all goes well today I will announce the winner of the frit. I believe it was the gal who posted second in this thread but I will need to go confirm. Thank you everyone for your help.

Also, I am still interested in trying some 5/64 but my supplier did not have those size rods.

gemsinbloom · #35 2010-09-09, 2:44pm

Lisa you are the winner of the frit! Can you please pm me your mailing info and I will get it out to you Monday or Tuesday morning.

Thanks again everyone.

Another problem solved!

Quote:

Originally Posted by GlassGalore

I think it's because you're trying to make too large a bead for that size mandrel. You just recently started making those larger pressed focals, right? I think it's a combination of the extra weight in the larger mass of glass, combined with the extra heat that mass will hold, and the fact that you work the bead longer due to its size. The mandrel is weakening with the extended amount of heat, and the weight of the glass is then bending the mandrel.

That's my theory anyway.

Frit Diva · #36 2010-09-09, 2:52pm

Hi Gems~ I just wanted to add that when you moved to a bigger torch, you may have gradually started making bigger things and working more aggressively without realizing it. That happened to me when I first moved from a Minor to a Lynx. I was already using thicker mandrels, but I did suddenly notice how much the new torch had changed the way I was working. That may part of the reason you didn't have the problem when you first switched.

Jo

gemsinbloom · #37 2010-09-09, 2:54pm

Yupp, I have heard this from a few now. I am also torching full time for a living now so I am needing to work hotter and faster.

I kind of wished I went to the larger mandrels earlier but better late than never, hehe.

Quote:

Originally Posted by grrlartist

Hi Gems~ I just wanted to add that when you moved to a bigger torch, you may have gradually started making bigger things and working more aggressively without realizing it. That happened to me when I first moved from a Minor to a Lynx. I was already using thicker mandrels, but I did suddenly notice how much the new torch had changed the way I was working. That may part of the reason you didn't have the problem when you first switched.

Jo

LynieG · #38 2010-09-09, 2:58pm

Ok - don't know how welding comes into this BUT! My hubby welds these GREAT big power poles and when they put them in the seam welder to close the seam after making the sheet metal round - the pole comes out bent because of the heat - it warps the metal - they then have to put the pole in a straightner and after that if there is still a bend in the pole they will heat it in different areas to make the pole straighten itself out! I guess mandrels would be along the same line if you are heating in the middle - the ends would warp where the metal was cooler! Unless you used a larger sized mandrel? Don't know if I'm right about this cause I have seen people work in the middle of mandrels all the time. It just got me to thinking and sounds logical to me but then again since when am I logical - LOL

Lisi · #39 2010-09-09, 3:56pm

i would never use 1/16" mandrels in the middle for anything larger than 13-14mm because then it would be in the flame too long. To make the larger beads in the middle, I would switch to 5/64", but to be on the safe side with those, run them through a kiln cycle before first use.

alb6094 · #40 2010-09-09, 4:10pm

I'm glad your problem is solved!

Ain't LE great?

Firebrand Beads · #41 2010-09-09, 4:16pm

Quote:

Originally Posted by Jenn L'Rhe

Someone here or WC suggested that torch heat and kiln slow cooling softened mandrels. I put mine in the cold kiln, ramp it up, pull them out and quench them in cold water to re-harden them. Then dip.

Are you doing this or just allowing the heat to keep softening them?

Kay

I have been making my own mandrels from 1/16 308L since 1991, and they do, indeed soften up with use and are more easily bent. When I tried the 316L, (on the advice of the welders supply, they called it a higher heat alloy) I was disappointed that my mandrels became soft much faster! I have gone back to 308L now. FWIW!

PerfectDeb · #42 2010-09-10, 2:00am

Quote:

Originally Posted by blong2001

Someone here told me that to temper the mandrels torch them until they are red and then drop them in to cold water.

Anyone know which is the better way to do it?

i do that to the first 3" or so and i heat them 3 or 4 at a time - cherry red then drop in my water jar
i find the bead release doesnt stick very well if i dont

Angie09 · #43 2010-12-06, 8:28am

Quote:

Originally Posted by gemsinbloom

Last night I created two beads on 2 3/32's I found in my studio. They come off the mandrel easily, easier and a dream to clean as well. When creating pendants with the larger holes, I filled the 20 gauge silver wire with seed beads, the length of the bead and zero wobbling!

Just an FYI ... you can purchase stablizing tubing and save your seed beads from http://www.smallparts.com. It works perfect for 3/32" holes!!!

Firebrand Beads · #44 2010-12-06, 11:02am

Quote:

Originally Posted by Jenn L'Rhe

Tempering your mandrels doesn't take any extra time unless you use all of your dipped mandrels each torch session and your bead release doesn't flame dry well.

I put them in the kiln during regular ramp up, it's usually up to around 850 when I pull them out and quench them (when I turn on the concentrator for it's 15-20 min warm up). Dip them while I wait for the concentrator. Easy Peasy.

You can also temper your mandrels cold with a hammer. Lightly hammering (no dents please) the softened part of your steel, against a block to make sure it's straight will stiffen it back up. I have never had luck with the 316L , they say it's a higher-temp alloy but what's good for welding (where they use these rods like solder) is not necessarily good for us, when we need these to stay stiff. I still have some of the 3/32 I made from 308 L in 1992, they are fine; the 1/16 I do have to replace more often. But when I tried the 316 I was suddenly BURNING RIGHT THROUGH the mandrels where I never had that problem before. I do think your 316L mandrels are softening faster than your 308L mandrels. Other people have made some great observations as well, like how the torque of working in the center and switching hands may be contributing to the bend. But try lightly hammering those mandrels before you dip them, and see if it makes a difference.

Leanne · #45 2010-12-06, 6:19pm

I use 1/16th for all my smaller beads and beads made with brass presses. for everything else though like focals I always use a 3/32.

dianeconroy · #46 2010-12-06, 7:17pm

I think the answer is that repeated heat "softens" the metal. My father is a welder machinist and this is what he has told me growing up. heating and putting in cold water tempers the metal and helps strengthen it. It may just be a combination of this and the size of your beads, as well as the metal has "softened and bends when you remove the bead, (this one happens to me alot lately)