Ultrasonic Cleaner for Moulds

[floodgate]

Someone here mentioned ultrasonic cleaning for moulds. I decided to follow up on the idea, and found that Micro-Mark <www.micromark.com>, who market modeling and small-scale machining tools and accessories, has two, one 6-1/2" long (big enough for Lee 6-hole and Lyman 4-cavity blocks, with room to spare, draws 50 watts, and has an auto-shutoff; they also make a 12-incher, but it is a LOT more expensive), their #82413, is currently on sale @ $96.90, and cleaning solution concentrate to make 2 gallons, #81870, is $5.65; total w/ postage - $107.53. I've gone ahead and placed an order and will see how it works out. A bit costly as compared with a jug of "Dawn" and an old toothbrush; but I have other uses for it as well.

floodgate

[Kraschenbirn]

Those rascals DO work quite well but be advised that ultrasonic cleaners and parts assembled using soft solder DO NOT MIX. The high-frequency vibrations apparently work-harden the solder and after just a couple of cleanings the joints become very brittle.

At one time, I had access to an industrial model large enough to clean most handguns w/o dissassembly and discovered...the hard way...that my local 'smith had soft-soldered the front sight on my Gov't Model bullseye gun. Was shooting the second timed-fire string of an indoor league match and, suddenly, couldn't hold any kind of sight picture because I couldn't find the front sight...which, at that point, was lying among the ejected brass on floor. Not realizing the cause of the problem, I took the gun back to the same 'smith who, again, soft-soldered a new front sight into the slide...and, a couple of weeks later, I lost that one during a rapid-fire string. (If you'd check my collection of Gov't Model "shooters" today, you'd find all the front blade either silver-soldered or dove-tailed into the slides.)

Bill

[montana_charlie]

Someone here mentioned ultrasonic cleaning for moulds.

I have mentioned it, here and elsewhere.
I clean both iron and aluminum moulds in a 1.5 liter ultrasonic unit.

For iron I use Micro-90, but switch to Surface-Cleanse/930 for aluminum.
I have the impression that Micro-90 is a bit harsh for aluminum.

A free sample of Micro-90 is available here ( http://www.ipcol.com/orig-site/prod-m90.htm ) and there is a link to the page for a sample of Surface-Cleanse/930.
The Surface-Cleanse/930 would probably work fine on iron, but two samples do twice the cleaning. (and they keep track of the fact you got your samples...)

I use a 2% solution, and siphon the solution off into a plastic juice bottle for storage between cleanings. That makes it easy to pick the cleaner that is right for the mould being cleaned.

A hot water rinse will remove the last traces of the detergent.

I fully dissasemble a mould prior to cleaning, and sparingly apply anti-seize compound as I reassemble it. Finally, with the mould closed and the cavity plugged, I spray the whole thing with two light coats of aerosol graphite.

If you plan to cast right after using Micro-90, get the mould rinsed, and dried, and lubed, and start the heating. If not, get some rust protection on the faces. Micro-90 leaves the steel absolutey clean...which also means absolutely unprotected.

CM

[Phil]

Just a note about ultrasonic cleaners. If you want to see if you have a good one, turn it on and stick a finger in it. If it doesn't feel like all the joints in your finger are about to explode, it isn't a good one. We have four of them at work and they weren't cheap but work wonderfully.

Cheers,

Phil

[floodgate]

Kraschenbirn:

Thanks for the "heads-up!", but I don't plan to use it on soldered assemblies (odd, actually, that Micro-Mark would not note this, as the auto, ship and RR models they offer have many soldered parts!?!) In fact, it might even help in removng lead-flecked areas on used moulds.

M-C:

Thanks for the info on solutions; theirs is not identified - probably an ordinary detergent

Floodgate

[brshooter]

Kraschenbirn;
45 auto's are noted for tossing thier front sights, expecially if there is any mass to them. Have you ever seen a front sight with a couple of holes, and very generous ones at that, in the side of it. The Bomar front sight is heavy and every time that slide slams home, the mass of the front sight wants to continue moving, eventually causing the sight to become loose and then fly off. With that sight installed with the small riveting protruction on the bottom of the sight pounded over and the use of soft solder to secure it, it is just a matter of time before it becomes loose and flys off. Reducing the mass of the sight by drilling as large a pair of holes in the side of it helps hugely. Mounting the sight, I mask the out line of the sight on slide with tape, then bead blast it. Then I tin the base of the sight and the area where the sight is going to be mounted with low temp "silver" bearing solder(8% silver, 92% tin), stake the front sight on correctly, take my torch and apply gentle heat to slide till solder glisens and maybe add a touch of solder, remove heat and you are done. No reblueing of slide because scorching due to high temp of regular silver solder. Done correctly, I have never had a front sight break off.
I don't believe a ultra-sonic cleaner will ruin a solder joint, I believe your sights were breaking off due to the soft solder and thier mass.

[Kraschenbirn]

<<I don't believe a ultra-sonic cleaner will ruin a solder joint, I believe your sights were breaking off due to the soft solder and thier mass.>>

Dunno...that particular Gov't Model had a lightened recoil spring and I'd put a few thousand rounds of "softball" (185 cast SWC @ around 725 fps) through it before the first failure which occurred not long after I started using the ultrasonic. The resolder job failed after less than a thousand rounds and a couple more cleanings. I never gave thought to the idea that the ultrasonic might have been the cause until I mentioned it to one of my customers (head of R&D for an electronic instrument manufacturer...and also a BP benchrest shooter who built his own rifles). He was the one who put forth the idea of the ultrasonic cleaner accelerating work-hardening of the solder. Said he'd encountered similar solder failures in electronic components subjected to high-frequency vibration and repetitive impacts.

As I said, this was a few years back and I haven't had any repeat since I started using silver-bearing solders.

Bill