chichi Posted December 4, 2009 Share Posted December 4, 2009 In the Foxfire book #5 there is a chapter on gun smithing flintlocks. The frontier gunsmiths years ago made their own springs for the locks they forged and(apparently unheated) quenched the springs in boiling lead. They were then dipped in linseed oil to "temper". Later, the springs were reheated to draw out the hardness. Does this process make sense or do you think the author of the chapter misunderstood? I think Wallace Gussler in the old video "Gunsmith of Williamsburg" demonstrates this but I cannot locate my video? Is this a process worth trying or is the burning oil technique reliable for springs? Thanks, Bob Quote Link to comment Share on other sites More sharing options...
John B Posted December 4, 2009 Share Posted December 4, 2009 IMO I think you have that the wrong way round. You have to harden first, then draw a temper. When I was a lad, to get an accurate tempering heat throughout a piece, the item was immersed in a molten bath of a known composition of tin and lead, much like we use molten salts today. By Adjusting the composition ratios of lead to tin, the temperature can be accuratley controlled, eg for watch springs or swords, we would be looking for a purple colour temper band obtained at 550F and so would have a molten bath of lead/tin ratio of 48 parts lead to 4 parts tin For larger springs, daggers, a slightly higher temperature would be required 558F and so a mix of 50 lead to 2 tin would be used. Now for some springs, (depending on application) or hand/rip saws blades etc BOILING LINSEED OIL would be used (600F) If you wanted to go a tad softer then MOLTEN LEAD would be used (612F) Just allow the piece to soak until it achieves the same temperature as the medium being used, then quench to fix it or let it air cool This may give some light to your reference, there are lesser ratios for other tempering ranges 7 lead 4 tin gives 420F, 10/4 gives 470F and so on Quote Link to comment Share on other sites More sharing options...
chichi Posted December 5, 2009 Author Share Posted December 5, 2009 I agree with the last post. The molten lead would be a good method for quenching a non magnetic piece . But the book says the spring was put in molten lead ( without heating the piece) , then quenched in linseed oil and later reheated to remove some of the hardness? It must be an editing error. Thanks, Bob Quote Link to comment Share on other sites More sharing options...
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