DirtyDaveW

I'm finishing up installing my new turbo/hotside which required rerouting of both the air filter tract and the turbo outlet to the intercooler. I had some left over 3" aluminum tubing from the original install back in '08. After trial fitting over and over and repositioning this that and the other, I finally arrived at a configuration that works. But, I only had one 90 silicone coupler and I needed two. Dang it... wait.. didn't I see a youtube about some aluminum sticks that they welded a hole in a thin a** coke can? I have a spare 3" "J" joint of the intercooler piping. I'll cut an elbow out of it.

So, I went and found that video and they used propane. Hmmm.. So I went and bought some alumiweld rods and got out the old Benzomatic propane along with some scrap 3" aluminum. Following the instructions, it took a fair (ie: too long for my impatient a**) amount of time to get to the 'melting point'(700 degrees) of the Alumiweld. This is because the thin gauge and the quick heat dissipation properties of Aluminum make it difficult for a marginal heat source such as Propane to reach/maintain the proper heat soak. Basically the way Alumiweld works is you heat the aluminum stock, then pull away the flame and wipe the Alumiweld stick on the hot surface. If the aluminum is hot enough, the Alumiweld will melt like a wax candle into the joint. Just keep rotating the flame over the surface to maintain the heat as you keep wiping the Alumiweld rod on the joint. Let it cool naturally(air cool) before using it.

So, I went to Lowes and bought a MAP/Pro TS8000 which has a larger tip and the inherently higher heat potential. I went back to my scrap and tested again. Ah, yes! Much better! The rod flows right into the joint and is strong (not bad looking either!) So, I’ll tackle the ‘real’ piping after I get back home (on the road right now at a client site). I’ll take some pics in case some of you other DIY’s are interested. I hope to weld some of the other connections to reduce the total amount of couplers I have. Those stinking things blow off at the most unwanted times.

Of course I'll pressure test it before 'going live' with it.

Kevin Blown 95 TA

I'm interested because I thought of doing the same thing rather than get a tig welder. I've used the rods one time before when I fixed a brake lever from my bike after it fell over and broke off. I had already replaced it with a new one, but I had the old one laying around and wanted to see if the stuff worked. And this was on a cast part, too. Anyway, the stuff did work (using Mapp gas) and much to my surprise, the repaired lever was really strong. The stuff was a little difficult to file down to the profile of the lever because it was harder than the surrounding aluminum. The hardest part of it was fixturing the two parts in correct approximation, especially since I didn't have a perfect fracture line to work with. I still have a bunch of the rods and was thinking of using it to manufacturer my inlet and outlet piping when I redo it, since my setup has outgrown the beginner kit ductwork.

So - yeah - I am interested in seeing how it turns out for you. I was wondering if it will be hard to get it to flow evenly all around the tube joint since either it is melted or it isn't and you are going to be heating up a relatively large area of the work. I think that just like with tig welding, the cleaner the better, with pre-heating. And maybe have a dedicated SS brush to clean the aluminum before you solder.

97WS6SCharged

Any pics of the experiment? I mean the pipes, not your singed fingers.

DirtyDaveW

Kevin,
Yeah, that aspect you mention of the "melted or not" was referenced in an article I found on the 'net. But they had a solution suggestion too. By 'belling' the opening on one, so that the other pipe could be seated inside the bell lip, you could create a 'cup' of sorts to retain the molten alumiweld. I think if I bell mouth the receiver and then position both pipes in a jig so that the pipes openings are horizontal, I can retain the molten weld. I'm hoping to get to this today or tomorrow. Spring my ***... this weather here in Upstate NY blows(no pun intended). Still snowing, still cold, still windy... I don't have a garage but I have a basement where I can try this.

On the SS brush and cleanliness, yes. I tried with a new brass brush I had but the molten weld/filler wouldn't stick. Vigorous brushing with the new SS brush before the welding worked perfectly.

I have my elbows already cut but I have to mock it up on the car while lying in the (alternately) mud/snow on my mat, then mark it up with a sharpie. Then I'll take it off, set it up with tack welds, try in the car and if all is still aligned, weld it fully.

DirtyDaveW

Well, I took some more scrap 3" and, using a crescent wrench on it's tip, tightened down on the edge of one pipe bent it outwards, all around the perimeter. Then I SS brushed both pieces I was joining. Then, I put the bell mouthed pipe in a vise so it would hold the pipe vertical, the cut/bell mouthed edge on tope, horizontal. I then put the other piece of pipe on top of the bell mouthed edge and started heating both pieces with the MAPP set on the lowest flame it could sustain. After the aluminum piping reached the proper temperature, the Alumiweld started flowing. I walked the flame and the alumimeld around till I completed the circumference. I let it cool fully and then tried to pull it apart. NO way! Strong and sealed. I got my trial fitting done and all is ready to weld up tomorrow.

Bigbadwhitey

Any pictures? Im really curious as to how well this seals and if itll hold up to pressure

97WS6SCharged

I think I'd buy a cheap pipe expander instead of using the crescent wrench.

DirtyDaveW

Hi, yeah. I already had one of those. Unfortunately, unless you've got it clamped in a vise (not good for thin gauge aluminum), it's just going to turn with the expander. I'm working on fabrication of a tool where I can use one of those expanders with a hydraulic bottle jack so that the jack can just push against the bevel in the middle and force the expander outward rather than that near useless threaded rod. I've torn up about 3 of those expanders trying to expand 3" mild steel exhaust tubing to 3 1/4" for a slip joint. The threads start stripping and it doesn't even expand the tube! I've drawn up the plans for the chassis to put the expander and the bottle jack within.

DirtyDaveW

Trying to upload the pictures from my phone now guys.
It was a success, I can tell you that.
Notes:
You CAN use the plain jane Benzomatic propane. In fact, the MAPP, even on low setting, is a bit too hot. The 'cupping' of the receiver tube works great and I recommend either that or expanding for a slip joint type fit. The finished weld is strong. I don't know what 'grade' of aluminum this alumiweld is but like you've heard and read, it's a LOT stronger than the aluminum tubing. It takes a serious grinder to get thru to. The first tubing I welded was the piping going from the turbo outlet. It goes down and then 90's to the front of the car then, 90's off to the left side of the car to meet the intercoolers routing. This is the one I cupped. After deflecting the perimeter of one of the elbows, SS wire brushing and marking both pieces for alignment while on the turbo, I gently clamped it in a vise in an orientation where the cupped surface would be horizontal, level. I then put the other elbow in the cup, flush surfaces, and with my alignment marks placed correctly. Using some welding rods as props to hold the top elbow in place, I started heating the pipes. Once the tubing reached approx 700 degrees, the alumiweld started to melt as I wiped it across the joint. Letting it flow, I walked the flame and the alumiweld around the perimeter till it was completely welded. After a few minutes, I pulled it off the vise and set it on the porch to cool for several minutes. I then got the 4" airfilter to turbo piping out, SS brushed and clamped in the vise. I thought on this piece, I'd just see if I could get the alumiweld to weld with0ut the cupping exercise. Just for grins. I worked too but you really have to work the flame carefully. Let it stay in one place too long and the alumiweld puddle will just drip off and hit the floor. Once that was finished, I took it outside to let it cool and started examining the first peice. I wanted to see if it had sealed totally. I took it inside to the kitchen, put some soapy water on the joint, sealed one end with my hand and putting my mouth over the other end, blew into it as hard as I could. Drat..a few pinholes. I wiped it down with brake cleaner, SS brushed it and went after the holes but tried laying it on its side so I could just address the pinhole I found. Bad idea with MAPP. This is where I found out it can get too hot. Even thought I'd turned the flame down low, it melted an edge of the actual aluminum and made a 3/8" hole in the pipe. Phock! Killing the MAPP and pulling out the old Propane, I covered the hole I'd created. Whew...

This created and blob of the alumiweld that, once cooled, I ground down. This is where I found that the hardness of the cooled alumiweld is so tough. I tried pulling apart the pipes with my bare hands. Not happening. I tried twisting the elbows apart. Nuh uh... can't.

I had to weld another piece of straight on to my existing straight to have enough reach to make it to the intercooler. The propane did the job fine and the first time. So, now all the intercooler/air filter stuff is on the car and bolted up! All that's left now is wiring the fans (using the stock fans as pushers) and welding up a small section from the down pipe to the Borla intermediate and the tough stuff is done!

The elbows before I started....


Showing how flush the cuts are...


Starting the 'belling'/'cupping' of one of the pipes...


Showing the insertion of one tube into the others 'cup'...


The welded piece...