Hey, couchspring. Yes, I use a ceramic block to solder on and prevent burning the table underneath. Some times I use a carbon block (a thoroughly toasted 2x4) Both are good resistors of heat and do not siphon away critical melting temperature from the parts being joined. I've heard it said that those who use building strategies / procedures like we do are employing both sides of the brain well. Who knows? Sometimes I believe that I don't use either side and things just happen that surprise me with the results. Muscle memory? An alternate self at work? I don't know, but it works for me (sometimes).
Hi, john k. I wish that I had one of those soldering tools. but don't know of such thing. I've used a spot welding instrument ( the sort that pinch sheet metal together and deliver a hot electric spark to join the two, and I've seen tiny models that jewelers use to attach earring posts (to the backs of jewelry pieces - not to the ears :) ). But I wonder if a heat iron could deliver 1200 degree temperatures to braze / silver solder heavier parts together. It sure would make my work easier.
Hi, turnnut. I'm glad that your eye procedure is behind you now, but the bleeding still sounds critical. I hope that you recover well and quickly.
I do think that I now have enough information to complete this jack project - slowly as it seems to be going. Will post some more pics soon.
Ralph
Ralph,
Is this jack 1/4 scale?
I have a spot welder. I tried it on sheet copper once out of curiosity. It didn't do anything. Seems that metal as conductive as the welders points just conducts the power on through. The resistance of steel is key, converting the power to heat and some light. I should try it on stainless steel. I imagine it would work great because stainless is such a poor conducter of heat. Because of that I assume it is also poor conducter of electricity, a rule of thumb that has a few exceptions.
The regular electric soldering guns don't get hot enough for silver soldering. A soldering iron rated at 65 watts or more will get hot enough to melt silver solders, but still may not work on bigger pieces due to their heat sinking properties. A lot of products are soldered with low temperature solders. I think the term is eutectic metal? If I remember right, eutectic metals are ratios of metals where the combination results in the lowest possible melt point of that group of metals. The alloy doesn't degrade or seperate into its parts when heated. It goes from solid directly to liquid state. This all results in very low temperature melting. Its the kind of solder used in solder link sprinkler heads. Fire sprinklers have melt temperatures of 135º to 286º normally, with some at 350º to 500º.
Non structural components can be joined reliably with these low temperature solders. Technically, what Ralph is doing is brazing. Jewelers and plumbers usually say "silver soldering" instead of brazing. Technically, solder has a melt point below 842º, while brazing temperatures are above 840º.
The structural difference is evident with copper plumbing fittings. Copper sweat soldered fittings have a big surface area compared to a welded or brazed connection. The join isn't strong and needs a lot of area to withstand the expected water pressures. For fire sprinklers that rating is 200 psi. When we braze copper tube together the join is small (< 1/4" wide.) The joint is very strong. Generally, the pipe tears before the brazed join when stressed, whereas if you rip apart a soldered join itusually breaks in the solder.
Silver solder comes in different temperatures. Generally used are hard (1365º-1450º), medium(1275º-1360º), and easy(1240º-1325º). There is an IT grade and its melt point (1370º-1490º) is closer to that of silver. I think you would only use it on fine (99.999 pure) silver(1740º melt temperature.) Sterling silver (.925 parts out of 1.000) has a lower melt temperature (1640º) than fine. There is also an extra easy solder (1145º-1205º). The higher the temperature, the more silver looking the solder is. Lower temperature gets progressively brassier in appearance. The brassier colors come from zinc, which is the metal most often alloyed with silver in silver solders.
Jewelers plan their fabrication so that higher temperature solder is used first, progressing down to the lower temperatures. By doing it in that order you help avoid melting previous joins. Often experienced fabricators can use a single grade of solder. If I have been soldering a lot I can get enough control to use a single higher grade consistently. It is easier to do with lower temp solders.
Professional jewelers often use lasers and weld their joins. Kind of like mig welding with a pure silver feed wire. Except the laser (pulses) feeds in small points or drops, heating and adding a small spot of silver rather than a continuous wire.
Chilly
