tiemze

anyone have experience with aluminum brazing? I got this idea from the vented valve cover thread, where someone used alumiweld to "weld" their bungs in. Seemed like a great idea because its very inexpensive and all you need is a propane torch.

Well fast forward to today. I bought the rods from harbor freight, did some trial runs on soda cans and was successful. I got the hang of it after I used about 2 rods. HOWEVER once I try to acutally weld my valve cover bungs in, It will never melt in like how it does on the cans. I've tried both a propane torch and butane. stripped paint off, and used wirebrush to get it very clean. I can get it hot enough to where the rod starts melting but touching the rod to the valve cover will not melt it. (thats how its done, melt the rod by touching the aluminum, dont melt the rod itself.) Can anyone help me out?

jere

You aren't getting the VC hot enough and or the cover is dissipating heat faster than the pop can. Find a better way to trap the heat in the VC, or get a bigger propane torch. Maybe try throwing the VC in an oven on full blast.

The best method is to put some braze on each component separately, then heat them together and join. So you are going to want to pre braze the fitting first, then the VC, then while the VC is still hot add the fitting. It helps to have a flat head screwdriver or chisel that you can heat up, to help smear the braze around too.

tiemze

ok i will try that thx.

tiemze

im gonna try mapp gas

tiemze

can you use a regular propane torch head onto a mapp cylinder tank?



i have one that looks like this. The ones they sell at homedepot are all fancy with starters built in but they cost over 50$.

now im looking at oxygen/mapp torches

btw i put the valve cover in the over at 350 degrees and it was hot! put it in a pizza warmer, I used to work at papa johns lolol. And tried the propane again....sat there for 10 min heating it and its still not hot enough.

tiemze

i finally got it on! i just needed a bigger torch!

i picked up the ts8000 from hd and it made the propane 10x hotter. i also put the valve cover in the oven at 350 degrees. that valve cover is super hard to heat up. for ts8000 and jere. also u cant use a propane torch on a map cylinder. im rlly happy.

jimbo slice

Care to post up some pics?

lostforawhile

i want to see this myself, definitely preheat the part, and spend the money on the proper mapp gas and oxygen setup, it works so much better then using a propane tip on a mapp gas bottle, I can't remember the type of acid you are supposed to pre clean aluminum with, but the aluminum immediately forms oxides on it's surface, this is why it's so important to clean

tiemze

its not the prettiest thing in the world but it got the job done. and it works! I can smell the vapors coming out of the can and no oil has collected in it at all so far, as expected.

To clean the aluminum i used acetone, lostforawhile, and where did i find acetone? Well my sisters nail polish remover of course

Soon I will repaint my valve cover, burned the **** out of it. aluminum unharmed, just the paint

and the catch can is in the back, cost me like 5$, hoses from autzone, goodyear pcv hose 6$.

lostforawhile

the acetone in fingernail polish remover isnt full strength, you can get the real stuff at any home improvement store, for aluminum it's supposed to be an acid, but I cant remember which, we have a tank at work, it's very specific on what to clean it with

jere

Glad it worked out for you, that stuff can get pretty frustrating. I bought a Oxy/Ace rig so I wouldn't have to mess with that low temp braze anymore. Alumiweld will get the job done tho, and it works on any non magnetic metal, pretty versitile. If you want to clean it up you can grind on it some (just take it easy and don't let the braze get too hot). Or you can heat up a screwdriver red hot and smear the braze to the point it looks like a weld.

vtechjunkie

iTrader: (2)

Cool alternative, but I will stick with welding. I would surely use this in a pinch though!

lostforawhile

I was thinking of getting a mapp/oxygen torch I think this would be fine for things like valve cover fittings etc, the torch I was looking at is also great for regular brazing,which a propane torch can't do. It's perfectly possible to gas weld aluminum, it's a skill which is mostly lost through. if you have 220 in your garage for an old kitchen oven, and an oxy,acy set, you can do it, I would just like to learn for the sake of being able to. I also have a vintage 40's audell welders manual, which is invaluable on the tricks to old school welding

tiemze

you can braze with propane. It's the head that makes the difference. Ever seen those weed burners? yeah..

I used propane to do this, when i bought that new head. The mapp it came with was hotter but I tried the propane and it still worked. besides propane is like 3 bux for a tank with map being triple