pboglio
15+ Year Contributor
- 1,799
- 85
- May 8, 2004
-
Palos Heights,
Illinois
Figured I'd share my experiences with my FMIC. I've had an ADFX Fmic for about 5 years now. Lately I've been running it up around 28-30 psi. Well last week it decided to split an endtank, and broke a bracket off. Decided to drop it off at my welder. Crack was in part due to not having an internal weld fillet reinforcing the joint. Unfortunately my welder missed the other endtank which also had a hairline crack in it. Since I can't get this guy to weld anything on the weekends, I decided to break down and attempt to brazing it myself.
I tried to use the Alpha Fry Braze for aluminum (53718) which melts at 1070*F, but had an impossible time attempting to get it to stick to the intercooler. I upgraded from a propane torch to a MAPP torch and results were the same after 10 minutes of preheat I gave up. Preheating the entire workpiece in an oven works well, but not practical in my case. With an oxy/acetylene torch it would be very doable I'm sure.
In a final attempt I tried Alumiweld from Harbor Freight. Cost $15 for 8x 9" rods which melt at about 730*F. Based on what I've read on the web, I was not confident this would work. This stuff gets a bad rap but when your desperate.....Directions recommend preheating, then testing the joint by scratching the surface with the braze/solder rod until wetting occurs. Previous to this a good brushing with a stainless steel brush is required to eliminate the oxide layer. After about 5 minutes of preheat, I was able to get a suitable braze/solder bead but I had to work in a strip about 2-3" long due to heat transfer and a small torch size. I could see major drawbacks in terms of productivity and speed as well since I was brazing/soldering about 2-3" per 5 minutes. I'd have liked to lay down a thicker bead, but being an outside corner, the best I could due was file a flat surface and get about a .060" thick bead laid down before it flattened out.
As far as testing, I used a hammer to strike the braze/solder joint and it appears there is a reasonably strong bond. I pressure tested the intercooler to 40 psi about 20 times and it holds leak free. So in conclusion, it seems to be a quick and practical fix if your down and need things repaired immediately for aluminum parts. I'll post some pics when I get it off the car to repaint it.
I tried to use the Alpha Fry Braze for aluminum (53718) which melts at 1070*F, but had an impossible time attempting to get it to stick to the intercooler. I upgraded from a propane torch to a MAPP torch and results were the same after 10 minutes of preheat I gave up. Preheating the entire workpiece in an oven works well, but not practical in my case. With an oxy/acetylene torch it would be very doable I'm sure.
In a final attempt I tried Alumiweld from Harbor Freight. Cost $15 for 8x 9" rods which melt at about 730*F. Based on what I've read on the web, I was not confident this would work. This stuff gets a bad rap but when your desperate.....Directions recommend preheating, then testing the joint by scratching the surface with the braze/solder rod until wetting occurs. Previous to this a good brushing with a stainless steel brush is required to eliminate the oxide layer. After about 5 minutes of preheat, I was able to get a suitable braze/solder bead but I had to work in a strip about 2-3" long due to heat transfer and a small torch size. I could see major drawbacks in terms of productivity and speed as well since I was brazing/soldering about 2-3" per 5 minutes. I'd have liked to lay down a thicker bead, but being an outside corner, the best I could due was file a flat surface and get about a .060" thick bead laid down before it flattened out.
As far as testing, I used a hammer to strike the braze/solder joint and it appears there is a reasonably strong bond. I pressure tested the intercooler to 40 psi about 20 times and it holds leak free. So in conclusion, it seems to be a quick and practical fix if your down and need things repaired immediately for aluminum parts. I'll post some pics when I get it off the car to repaint it.
