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stegmo2
21-02-2006, 10:01 PM
Is there something out there that will work for soldering an aluminum evaporator? where can I get it?

Thanks

Paul

chillin out
21-02-2006, 10:39 PM
For a supermarket???? Forget it.

Even for a domestic....forget it.

Chillin:) :)

Erik Detroit
21-02-2006, 11:02 PM
For aluminum it's not called soldering, it's called brazing but the process is fairly similar.

The best joints are made with alloys that melt only slightly below the temperature of the base aluminum, so it's a very tricky job, and requires a lot of practice. You can google "aluminum brazing" and get a lot of different mfgr.

There are other alloys out there with lower melting temperatures, and these are much easier (probably not as strong??).

http://www.muggyweld.com/super5.html

I've never personally tried this muggyweld alloy, but I know people who have used it with good bonds, but on what I would call "lightly loaded" parts including some automotive evaporators.

CONROD
21-02-2006, 11:41 PM
Hussmann used to fit aluminium evaporator coils in their shellette cases. They leaked frequently and were unrepairable, the coils had to be changed. Soldering alumnium is a specialist job, very tricky.

phil68
22-02-2006, 12:04 AM
I've done it in the past, but only on motorcycle parts using a product called Lumiweld. You have to heat the whole item up in an oven first then use a low-powered blow torch to melt the rod into the repair. The trouble is that the temp. required to braze ally is also very close to it's melting point & the transition is very quick, not helped by the fact that the ally gives little or no indication that it's close to melting, unlike say copper which glows a cherry-red colour & then bright orange when it's about to melt. Also everything has to be scrupulously clean for the weld to take. I've also had a go at mig-welding ally in an amateur capacity & have to say that steel is 10 times easier as whatever I did with the current it would either blow holes in the work piece or just lay blobs on the surface:) As the other guys said, definitely a specialists job.

Andy W
22-02-2006, 09:32 AM
Is super poxee no longer used, years ago it was the thing to use on leaking or stabbed evaporator coils or on aluminium suction lines when compressed / joined into a copper suction, on a firm I worked for in the 80's they would not but super poxee but insisted on using 2 pack araldite glue, oddly enough, it worked.:eek:

Karl Hofmann
22-02-2006, 05:43 PM
The Muggy weld seems to be good stuff, but I have never used it, I have used a Canadian product called Braze Perfect, and that does work very well but it does have a melting point very close to the alloy so you have to be very carefull, it pays to practice before hand to learn just how it works. the down side is that the area has to be very clean and any trace of corrosion will give problems. Lumiweld is good for general alloy repairs, but when working on joining or repairing pipes it just does not seem to give a gas tight seal, use an alloy braze that uses a flux rather than the stainless steel "scratch" rod.

Have fun

NIKK38
15-04-2008, 10:19 PM
change the coil, it's the only good fix.

old gas bottle
17-04-2008, 03:27 PM
forget the resins,the hot/cold nature along with the damp gets behind it and it never lasts,also the higher working pressures of modern gases will finish it off,i gave up on trying to weld those things 15 years ago, it would be worth a try if it was good grade ally to start with but seeing that most of it is crap theres not much hope.:eek:

Gwyn
23-04-2008, 11:08 PM
I usedto use a stick from NRS called 'greenstick' worked well on the domsetic evaps. tricky to do but as long as you donnot apply heat direct to the stuff (heat from the other side) it just works!
good luck.

duarte
23-04-2008, 11:54 PM
Try to get from somme hardware store:
-WURTH LIQUID METAL (a+b), or similar.
If you have a big hole, be carefull.

daddyfixit
24-04-2008, 02:55 AM
Have you considered using C-4 :eek: on it. You wouldn't have to worry about that coil leaking any more.....;)

Of course, there won't be any coil to leak left.....


I'm for the coil replacement. I've tried the aluminum braze and it isn't for the faint hearted. I used to think I was a patient man until I tried that.:mad:


Wish you the best.....

Toddraptor660
25-04-2008, 03:50 AM
I work for a supermarket chain and we have alot of the old Hussman uprights NF6L-12U. These cases have an aluminum coil, we have had good luck with taking the coils out and taking it to a welder here in town and he tig welds the problem area and then we put the coil back in. Its alot of work but saves the price of a new coil and also gets the case up faster as there is most times a long wait on the coil that was suppose to be here yesterday.

joe magee
12-05-2008, 07:46 AM
Rsd carries aluminum brazing rods. The best advice I can give is clean area with 409 and a stainless brush. P.S Find a scrap piece and practice first. On the Hussman riff cases I use to cut out a pass were the copper side was. I never had a problem reaching -8 with two passes left.
Good luck