FullMetalFab Posted November 28, 2012 Share Posted November 28, 2012 hello my my name is zach and im new to black smithing/ bladesmithing. I have build a forge at my metal fabrication buisness, it is a freon tank with a 6 inch sonatube center with castable refractory for insulation. it seams to be working ok but im having some trouble with my forge welds holding, ive been trying my hand at some damascus blades made with 1095 5160 and 15n20. my problem is that im having delamination seams to be only around the areas with 15n20. Im thinking not enough heat.... my forge has 2 forced air burners, instead of a blower ive been using my air compressor, with valves to regulate, im thinking that its still to much pressure and not enough volume. ive been runing about 10 psi, although ive tried up to 25. ive messed with the air flow from really lean to running it really rich. I understand that i should have some dragons breath or small flames coming out the front door and i should have it runnning a little ritch to avoid an oxygen ritch atmosphere. now i do have some water in my air lines, is this possible that the water in the lines is somehow cooling my burn..... any ideas would be greatly apreciated, I have attached some pics of my forge. Quote Link to comment Share on other sites More sharing options...
Rich Hale Posted November 29, 2012 Share Posted November 29, 2012 This was just covered in another area,,Knives I think...TGhat asde, 15n 20 and 5160 both contain nickel. Nickel does not like to weld to nickel. Lose the 5160 and see wot happens,,,Hard to see wot your experience in orge welding has been. And you also may have issues with your forge set up....to much air will scale up more. You did not mention if you are using flux or wot kind. Quote Link to comment Share on other sites More sharing options...
Dave Hammer Posted November 29, 2012 Share Posted November 29, 2012 Are you using anything for doors on your forge? Quote Link to comment Share on other sites More sharing options...
FullMetalFab Posted November 29, 2012 Author Share Posted November 29, 2012 sorry about the lack of info, I am using hard firebrick doors in the front that i just leave a small opening to put in and remove my billet, in the back i have 2 firebricks blocking it completely. as for flux i am using borax, after a little messing around today I think i am having a problem with lack of heat. i am going to try a shop vac on blow as a blower and T it into my burners, I think that my 1/4 air compressor fittings and compressed air has too much pressure and not enough volume.... as for silver to silver, i actualy tryed a peice of billet were i stacked 2 layers of 15n20 and then one layer of 5160... the better welds seam to actually be between the 15n20 and its self... so ya.... kinda at a losss. Quote Link to comment Share on other sites More sharing options...
Dave Hammer Posted November 30, 2012 Share Posted November 30, 2012 You might try using soft firebrick (IFB) for your doors instead. Coat the brick with a ceramic refractory for more efficiency. If the interior of your forge comes up to forging temp quickly, the hard firebrick doors may be sucking up a lot of that heat. Hard firebrick should work, but it may take the burn chamber a lot longer to get to forging temps. I'm not sure if a ceramic refractory coating can successfully be put on hard firebrick. I'm no expert at forge welding, but be sure you are patient with regards to the materials being heated to welding temps all the way through. Be sure to "soak" the materials throughly. Heat it to where you think it should be, then let it soak a bit more before you weld. Quote Link to comment Share on other sites More sharing options...
pkrankow Posted November 30, 2012 Share Posted November 30, 2012 You can put a refractory coating on hard firebrick just fine. An IR reflector coating may be of value. However coating hard firebrick does not change it from being hard firebrick. Phil Quote Link to comment Share on other sites More sharing options...
FullMetalFab Posted December 2, 2012 Author Share Posted December 2, 2012 I changed from a air compressor, to a shop vac on blow, I used 2 large ball valves to regulate. i did get more heat and seamed to get better welds, I think that i need better doors ( any more sugjestions). and i have the valves allmost shut completely off, I just bought an 80cfm 4" ducted fan. I think this will have a less static pressure and alow for better welds with less oxegenization... any more on this? Quote Link to comment Share on other sites More sharing options...
pkrankow Posted December 2, 2012 Share Posted December 2, 2012 Get a few soft thick firebrick, weld or bolt on some channel or angle that the fire brick just fits to hold the brick against the openings of the forge. Make up a pair of lightweight tongs for grabbing large materials (fireplace log tongs) to adjust the bricks to a suitable opening. One step easier is to use a cinderblock (cheap but not heat resistant) and thin hard firebrick (cheap and highly heat resistant) to stack a porch in front of the forge on the table, then stack soft or hard firebrick on the porch to make a door. Phil Quote Link to comment Share on other sites More sharing options...
reefera4m Posted December 11, 2012 Share Posted December 11, 2012 I just read this thread and I have to disagree about 5160 containing nickel. I use 5160 a fair amount and to my knowldege is lacks any nickel at all. It is sometimes difficult to forge weld but I believe that's the chromium. On the other hand it welds easily with a MIG welder - and makes excellent anvil tools like cut-off hardys. It also makes a good blade on its owm Admiralty Steel and others show 5160 as: Carbon 0.56 - 0.64 Chromium 0.7 - 0.9 Manganese 0.75 - 1 Phosphorus 0.035 max Silicon 0.15 - 0.35 Sulphur 0.04 max This was just covered in another area,,Knives I think...TGhat asde, 15n 20 and 5160 both contain nickel. Nickel does not like to weld to nickel. Lose the 5160 and see wot happens,,,Hard to see wot your experience in orge welding has been. And you also may have issues with your forge set up....to much air will scale up more. You did not mention if you are using flux or wot kind. Quote Link to comment Share on other sites More sharing options...
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