RXFORD Posted February 26 Share Posted February 26 The only real 'controlled' way to shrink is oxy/acet heat shrinking. You were kinda on the right track, but most likely heat up too big of an area with the butane. Firstly find a dolly thats either the same crown or slightly less of a crown as the panel/area you are shrinking and grab a flat faced panel hammer. Onve you have identified the area thats too full and needs shrinking, use a small gas welding tip (not a big cutting tip) and heat up a small 5c coin sized spot til cherry red, then while its still red, start lightly hammering it. I set myself up something I can safely chuck the torch over so I can drop it and start hammering. The initial blows might have to be a bit harder to dress the swollen centre down, but then for the next 20 seconds or so, just lightly dress the surrounding 50mm radiused area down. It should now be cool enough to touch. It will still be warm, but nothing crazy. The light hammering just helps control the shrinking while cooling in that area. It may shrink slightly more once its completely cooled depending on the location, but at least it won't do any weird shit because you kept it localised and told it what to do. The idea behind the lower crown dolly and flat hammer, is to dress the material into itself, rather than stretch which is what would happen with a higher crowned hammer and dolly. The concentrated pinch would just start stretching again. Don't use any form of wet rag or air to cool it. Just the hammer/dolly, then let the rest cool naturally. Shrinking discs work ok sometimes but it has to the 'perfect' high spot. Once you get good at heat shrinking you'll be set. 3 1 Quote Link to comment Share on other sites More sharing options...
tortron Posted February 26 Share Posted February 26 Can you get fine tip for lpg? For me at least an oxy act rig is a bit much admin Also, practice on something else first. My ute was evidently the apprentice practice rig when it was built by the workshop judging from, well everything.... The roof had been shrunk with a torch, but they fucked it up, lost most of the crown, ended up just pushing it in and carving a new one out of bog A disk is certainly fairly amateur friendly, it doesn't shrink too much in one go sort of thing This was a good video 1 Quote Link to comment Share on other sites More sharing options...
Nominal Posted February 26 Share Posted February 26 There is a lot of info online that might help identify where you need to shrink or stretch. I like the allmetalshaping site as there are some very experienced people on there e.g. first result off google e.g. https://www.allmetalshaping.com/showthread.php?t=11929 Kent at tinmantech, MP&C and John Buchtenkirch are all worth listening to (reading) 1 Quote Link to comment Share on other sites More sharing options...
tortron Posted February 26 Share Posted February 26 Oh another thing I picked up from one of thesw videos was finding the point in the oil can that needs addressing. Using both hands you go around the area that pops in and out. At some point you will be able to press down on one spot and the rest won't want to pop any more Quote Link to comment Share on other sites More sharing options...
nzstato Posted February 26 Share Posted February 26 +1 for shrinking discs. You can buy em direct from the OG, Wray https://www.proshaper.com/product-category/shrinking-disc/ Quote Link to comment Share on other sites More sharing options...
tortron Posted February 26 Share Posted February 26 35 minutes ago, nzstato said: +1 for shrinking discs. You can buy em direct from the OG, Wray https://www.proshaper.com/product-category/shrinking-disc/ Yeah that's where I got mine. Better than an old pot lid for sure 1 Quote Link to comment Share on other sites More sharing options...
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