| Author | Message | ||
     Torquehd |
I'm having some difficulty finding specific fasteners online. I'd like to purchase some M8-1.25x30mm button-head torx fasteners, preferably black anodized.... Any ideas? Fastenal only seems to have SAE/'Merican threads. It seems like there should be a site where you can select your thread, length, head style, driver style, and coating options, but i can't find anything like that. Additionally, has anyone ever tried MIG welding cast aluminum? I'm working on a project that may eventually require welding some extruded flatstock onto a piece of cast. Or will I have to settle for making it a bolt-on piece? (Message edited by torquehd on December 07, 2013) | ||
| Torquehd |
nevermind the fastener part, I was looking at in the wrong place on Fastenal's website. | ||
| Reepicheep |
I watched a friend MIG weld a cracked cast Porsche 914 rotor. I was expecting it to be really complicated, but he just clamped it back together, put in a few stitch welds, then covered it with a multi layered welding blanket so it cooled slowly. I think he later went back and put a bead along the whole thing. | ||
| Torquehd |
Nice. Thanks! | ||
| Aesquire |
There are tricks to welding Al. You make the heat treating go away along the seam, for one thing, and the cooling is important. If you are doing it, practice on some scrap bits. Make sure you have the right alloy wire. Pro's do it all the time, so if it's a single or just a few joins, have it done by an expert. You live in WA. IIRC there are a few truly expert aircraft companies there. Glasair, CubCrafters, Composite Aircraft Technology, Northwing, etc. ( I'm looking at buying a Northwing ) There's a big one, but I forget the name.  http://www.afa-wa.com/directory.pdf | ||
| Reepicheep |
(Minor correction, it was the caliper, not the rotor obviously, Porsche didn't put aluminum rotor on a 914  ) | ||
| Natexlh1000 |
I've had good luck with McMaster at work. You can select criteria from a list. | ||
| Torquehd |
rhymes with Boeing? i have some cast and extruded i'll experiment with before I do it on the final piece. | ||
| Etennuly |
I weld this stuff with a MIG all of the time. It works well, you can get good strong safe welds. It does not matter if you are welding cast and extruded together. The most important criteria is cleaning before welding. Use a stainless brush on a drill. You must have an oil free near polished finish for a good weld, on all sides. If you grind a weld groove with a stone or grinding disc clean it with the stainless brush before welding. I use pure Argon gas and there are a few different wire types you can get along with hardness differences. Generally I use the softer wire for both extruded and cast. The harder wires tend to push through the weld puddle on the extruded stuff. MIG welding aluminum is fast. It takes about 40% more heat than steel for the same thickness, all of that heat means faster wire feed, meaning you've got to be ready to make your pass as you start the trigger. I like to be moving the gun as I start the weld to prevent burn back, because aluminum wire will swell up back into the tip if it jambs a little. I use an .035 tip for an .030 wire to avoid some gumming and jambing. Have some extra tips on hand. I often take a number drill and open a couple thousandths relief area an sixteenth of an inch back into the tip. This can allow the wire to wobble a bit coming out. That sometimes actually helps by being a consistent wobble movement that will allow you to get a nice "stack of dimes" weld while moving the handle in a straight line. A disclaimer; almost all of the aluminum welding I do is on the repair of used(not new) parts and materials or welding of new parts to used parts. Also the majority of what I weld is in it's real world position. What I do is often short of the luxury of new materials on a bench in a shop, this does make a difference. A lot of what I do is vertical and even upside down welding. | ||
| Torquehd |
Thanks for the pointers. | ||
| Oldog |
Wow Vern if you can weld overhead with aly in position you are good.... when you weld in the vertical do you weld up hill or down? | ||
| Etennuly |
On vertical welds I start at the top. I have not been able to make an aluminum puddle flow up hill, but a thinner streaming weld will go up, but they are thin welds. You can stack spot welds but I like a vertical single pass in a groove followed up by a weave weld over that for strength. Jim.....you ought to see my welding jacket. It has been on fire so many times. It took a couple of years to find the technique that works upside down on aluminum. Mostly I do that on box truck extruded top rails that have broken at the top edge. It takes about $1200 to replace a 24' top rail that has split. The truck companies like it when I can weld repair it for $3-400. I also repair a lot of aluminum truck box entry walk ramps. Rental customers tend to break the brackets off from them by not understanding how they work. If it is a single weld I usually will crawl under and weld it upside down. Mostly though, it is take the ramp out and rebuild all of the working hardware and brackets. I also repair a lot of aluminum bumpers and steps. |
