Lapidaryforum.net
Gadgets, Gizmos, and Dohickeys => Fixing, Modifying and Refurbishing your Lapidary Equipment => Topic started by: robirdman on February 26, 2018, 03:19:25 AM
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Like other problems with equipment in storage for a year after fire hose flooding, I have one with this Megasonic disintegrator, which I used before to drill stones. This was by means of a brass bolt that was screwed into the bottom of the drilling area with a piece of steel tubing soldered onto the tip. A SiC slurry was sprayed on and did the drilling. It was difficult to find brass bolts, but I eventually did and then ordered some fine steel tubing. But when I try to solder the tubing I keep failing. First I tried standard solder for wiring but that just beaded up with the Oxyacetylene torch. Then I think I remembered that I used silver solder before. I have some marked 1200 and got some flux at Home Depot. I cleaned and sanded the parts but they didn't bond again. Then I looked at the only remaining bolt that was still in the drill. The tubing was wider and it was in a hole drilled into the bolt. Unfortunately bent and unusable though. So I drilled with the new bolt, and put tubing in, but it is loose because the tubing is smaller. Tried anyway, heating all red hot after using the flux and solder and loose, didn't bond again.
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Silver solder is correct for stainless but you must have a contact fit. I would also want a softer alloy for this purpose. The tube that contacted lead solder is contaminated and will need to be cleaned with abrasive.
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I didn't resuse the smaller tubing and sanded the bolt head. Going to get the smallest drill size I can, because I had broken the one in the set I had previously.
Is this a suitable flux? On the back it has direction for soldering pipes, which makes me wonder.
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Is this solder suitable for this purpose?
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That would be a definite no on the flux. That flux is for lead solder and specifically excludes stainless steel. I just use borax for flux. As to the solder, I'm guessing you meant to include a photo.
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Thanks. I'll get borax and make a mix with salt as I read. You're not seeing the picture of flux that I am?
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You might try brass brazing rod, the kind with flux on the rod is easiest.
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Looked that up and a Home Depot near me indicates online that it has 1 in stock. Sounds like a plan.
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We had a customer who wanted to use brass to braze stainless points to wire for stun guns. Silver solder is the method currently in use but it is expensive in large numbers. We put a lot of effort into this as it might have saved us money on stainless treble hooks as well. We did get some good joints but in the end we just weren't able to achieve a reliable process.
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I have been doing this for decades. I just ran out of the flux that came with my ultrasonic drill (after 20 some years) and Bobby 1 recommended Handy Flux. I bought both the white and black and opened the black first and it works very well. Take a small stainless steel brush and brush the area of the bit that is getting soldered and then dip that area into the flux. Even covering is important as the solder will not flow if the flux is missing in that spot. With my horns there is a dimple on the end called a pot and it is filled with silver solder with a bit of flux. I use map gas pro which is barely hot enough but is convenient. If you heat the tip until it gets red you have made it brittle. I melt the easy solder, jewelers silver solder, in the pot with a tiny bit of flux placed on it to help break the surface tension. I do not hear the bit but hold it above the flame hitting the pot for about 5 seconds to dry the flux then in one motion move the torch flame down from the silver solder and at the same time immerse the bit in the solder.The correct flux is a must period.
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My system is different. The drill head accepts a threaded bolt, onto which a steel tube has been soldered. Years ago I had prepared a lot of tubes soldered to bolts, but they all got discarded after my house fire. It was quite a problem to find non-steel bolts and I finally found the brass ones online. Then I thought the ultrasonic drill tubes were what I needed and ordered 3 sizes. At first I just tried to solder onto the bolt and failed. Then I saw that there was one remaining bolt in the drill, with a bent tube, and I saw that it had a hole drilled to accept the tubing. Unfortunately even the largest tube was smaller diameter than the smallest drill bit I had, and when I tried to solder again, it didn't work, but I see that the flux was wrong as well now. I was missing the smallest size in my drill bit set and got the smallest at Home Depot, only to return home and find that it was the same size, and that the set had 2 slots for 1/16" so the missing one was no smaller. I also got the brazing rods and it seems that I successfully soldered the tube, even though the hold is larger, like it filled in. I tried a 2nd one though without success, maybe because the flux coating receded so far with the first one. Should I have cut a piece off, instead of just holding to the parts? A picture shows 3 bolt/tube combos. The old, larger diameter bent one, the successfully soldered one, and the failed one, which is pointing up. I just screw onto a nut to hold upright, when doing this. Also the state of the brazing rod. Further advice is appreciated.
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I would drill a hole at least 1/4 deep and at least 3 times the drill tube width in the bolt so it acts as a pot as in my horns. I would say silver solder and handy flux.
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I had to get a new pump to spray the SiC slurry. Grainger's was very helpful in spending a lot of time to track down the replacement for the decades old one that I brought in, and which was no longer in catalogs. It is 1/77 HP like the previous. I tested out with just water and found that the basin fills up quicker than it drains though. If I solve that, I'm also wondering about a better way to hold the spray nozzle in place than using a visegrips.
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lithic beads: Any suggestion on how to reduce the flow? Would a longer tube help or when the SiC is added to make a slurry. I wonder if I could see a picture of your setup. Here is mine.
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You could drill a hole in the side of the delivery tube so some of the grit -water would fall into the tank rather than being delivered to the work area
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I use grit trays. Loose grit in a pile with a water drip that is variable.I use very little water. The end of the stainless steel tray has a piece of hose cut on a bias on the down hill end to deliver the grit accurately.I have made these out of quart milk containers cut long ways duct taped to a dowel.
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I finally came back to this after I successfully soldered one tube to a bolt, and used a smaller tube directing the spray. I added SiC and got a spray going in balance with the uptake so the basin doesn't fill. I think the instructions were lost in the 2010 fire I had. I powered on, and wasn't sure how much power to use. When I moved the dial farther to the right, everything went off, as the socket circuit breaker kicked in. I reset and tried again not going beyond the blue level, bu
t I don't know how much intensity to use with the other meter, which goes up to 30. I used the foot switch and held a stone under the tube but didn't seem to be noticing much if any vibration with the pump and power noise. After I turned off and even unplugged, I was still hearing some noise in the power unit.
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If you can run it for testing with the pump off it would be less distracting.You can use a small plastic container of very wet grit and put the end of the bit in that. It is essentially the same as when you drill big flats with my drill so there would be enough grit but no distracting noise.
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That's an idead. What kind of settings does your unit have and that you set?
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If the bit isnt in the water grit mix it can sometimes vibrate itself off the horn. Mine is largely automatic but gouing too high will often not work. If the solder joint is bad that can stop the bit from vibrating even if it does not come off the horn. Do you solder your bits on or use acoustical washers?