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Bench vise as heat sink?
Posted: Sun May 01, 2005 4:11 am
by Alcyoneus
Are bench vises heat treated in any way? I've got a project that I may need to use one to hold metal that I need to heat a very small portion of, and wouldn't want to damage the vice.
Posted: Sun May 01, 2005 1:23 pm
by Thomas Powers
Most bench vises are plain cast iron and so are not heat treated.
If you are worried you can cut out a couple pieces of haeavy angle iron and use those to cover the jaws and spread any heat that hits them
Thomas
Posted: Sun May 01, 2005 1:30 pm
by Minotaur
Not all but most have treated jaws and screws with a cast body. I use my vice to hold stuff that I am welding all the time. It depends how close to the jaws your going to be heating and for how long.
Posted: Sun May 01, 2005 10:54 pm
by Hew
Aside from possible damage to the vise, if you used insulating jaw covers I should think it would allow the piece to be heated up quicker, since the vise would not be sucking away all the heat.
Maybe two blocks of pumice from the Bath Accessories section of a drug store? Tiles from the space shuttle?
Posted: Mon May 02, 2005 8:03 am
by Cap'n Atli
As Thomas suggested, angle iron should work, the heavier, the better. If you want additional heat-sink, you could clamp a couple of steel (or better yet brass*) bars to the work above the vise. Mass is good! Or you could just wrap a wet rag around the base of the work down by the vise; it will start steaming around 212 degrees, well below any temper change.**
*...or for the ultimate in heat transfer, large silver ingots; which will be ruined, but you can send them to Thomas or I for recycling.
** Some methods used in dirt-floored, coal burning blacksmiths shops may be deemed inelegant and messy, but they sure work for me!

Posted: Mon May 02, 2005 9:53 am
by Thomas Powers
For large enough ingots we have a collection service---especially if you are withing raiding distance of navagable waterways...
I think he wants to use the vise as a nail header and so will head the head portion with a torch to soften for hammering. bench vises not being suitable for hammering I have suggested a nail header.
Thomas
Posted: Thu May 05, 2005 8:15 pm
by Hew
Cap'n Atli wrote:As Thomas suggested, angle iron should work, the heavier, the better. If you want additional heat-sink, you could clamp a couple of steel (or better yet brass*) bars to the work above the vise. Mass is good! Or you could just wrap a wet rag around the base of the work down by the vise; it will start steaming around 212 degrees, well below any temper change.
I think the idea is to
minimise the heatsink effect, and keep the heat in the piece being worked on, hence the insulating jaw covers.
Otherwise, it's like trying to solder copper plumbing with a little pen-type soldering iron. Less mass heats up faster. If it heats up faster, then the clamp holding it does not get subjected to as much heat.
Posted: Fri May 06, 2005 3:56 pm
by Thomas Powers
Hmm the only semi insulating jaw covers I could think of that would thake the hammering these will se would be made from Ti---are there others you had in mind Hew?
Good Idea though now to get my stock of large Ti milled for jaw covers...
Thomas
Posted: Fri May 06, 2005 7:36 pm
by Hew
Thomas Powers wrote:Hmm the only semi insulating jaw covers I could think of that would thake the hammering these will se would be made from Ti---are there others you had in mind Hew?
Hmm... hammering wasn't specified in the design spec.
That could be tricky, since a lot of candidates are ceramic, granular, compressible, or flammable.
Good Idea though now to get my stock of large Ti milled for jaw covers...
Titanium?
From
http://www.reade.com/Particle_Briefings ... etals.html
Material ---> Thermal conductivity, in (cal/sec)/(cm^2 C/cm)
Aluminum = 3.00 (popular choice for electronics heat sinks)
Iron = 1.32
Copper = 4.83
Lead = 0.396
Titanium = 0.312
You might have something there, for a choice of metal.
See
http://hyperphysics.phy-astr.gsu.edu/hb ... thrcn.html - lots of non-metallic materials, like insulating brick are way lower, but are otherwise unsuitable (helium? water ice? cork?).