Is it aluminum or magnesium?

I have a small part on my VW sun roof that needs to be repaired. I'm not able to get my hands on a new part so I'm wondering if there is another way to fix it. "WELD" it, I have a Miller 175 (Argon) in my shop but can't figure out if the part is aluminium or magnesium. The broken part seems to be very porous and soft. Any ideas how to go about repairing a small part with only 1/8 inch of surface to weld?

Reply to
HotRod
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If there is an area that you can scape off a few shavings with a knife, and then hit them with a propane torch, you may be able to tell if they are magnesium if you can get them to ignite. If they are mag, you will get a very intense white flame. Make sure they are small slivers, and do it on a nice steel table of cement floor well away from flammables, as magnesium fire is HOT.

Dave

Reply to
Dave Nay

Any ideas on how to repair it?

Reply to
HotRod

Here is an option if it is pot metal

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Reply to
Rusted

Metal powder filled Epoxy putty. Permatex Strong Steel Stick is a favorite of mine.

Reply to
Ernie Leimkuhler

I will give it a try and see how it works. I have nothing to lose at this point. It's a pretty small area but I guess we'll see. THANKS

Reply to
HotRod

Tried the JB Weld last night but it just didn't work, I'm guessing there is to much pressure on it. I called about getting a new part and after a few hours of talking to the parts guy I found a part number and a price. This little 3 inch long guide for the sunroof is $280. I think I'll be calling some junk yards.

Reply to
HotRod

You don't mention the specific model you are looking for, but I wish you luck. I have found that VW parts for most models are difficult to find used. And of course, when you do find them they have the same problem that you are seeking to solve.

Just my experience. You may want to check out: rec.auto.makers.vw.watercooled and see if anyone over there has what you are looking for.

JW

Reply to
cyberzl1

I've already checked there but thanks. I just can't believe that this little clip is almost $300 CDN. I'm thinking about trying to cast my own part, I could spend a whole week of night playing around and still come out ahead. As long as it works...

Reply to
HotRod

Is the break in an area where there is a reasonably flat surface that doesn't contact anything? I have fixed a number of items that wouldn't hold if I simply glued them due to too much stress on too little area. But if I could glue the break and glue a piec of aluminum sheet to the surface over the break, it would hold.

Ted

Reply to
Ted Edwards

Actually it's an "L" shaped piece roughly 1/4 high and 3" long it starts about 1" wide and then tapers down to 1/4 inch. It's the 1/4 end that's busted off. What glue do you use to attach these aluminium pieces. the 1/4 piece is only 1/4 long as well.

Reply to
HotRod

Have you given any thought to having it milled out of aluminum? It will likely last longer than pot metal, although not look exactly the same. Probably cheaper than casting it, especially when you look into the hassle factor.

Reply to
carl mciver

I'm going to keep looking into this but I'll figure it out next week when I have some time to give it more thought.

Reply to
HotRod

Do you have both pieces? If so, use super glue to re-attach the broken piece and use the result as the pattern for casting. The super glue bond will be strong enough for molding, but not for use on the car. I have done this with parts.

Bob

Reply to
Bob Engelhardt

How about a piece of aluminum angle iron (1x1 sounds right) of the appropriate thickness? Cut, file, jig saw, table saw, snips. Take away the parts you don't need and keep the little bit that you do need.

(top posted for your convenience) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Keep the whole world singing . . . . DanG (remove the sevens) snipped-for-privacy@7cox.net

Reply to
DanG

today i was wondering... what economic reason would compel a manufacturer to use magnesium over aluminum? and, more importantly, how in the hell do they cast magnesium if it is so prone to rapid oxidation?! (i just did a simple google search and found a few things but none seemed to address my questions) i'm thinking the fact that magnesium burns is exaggerated. i can't imagine they would melt and pour liquid magnesium in an inert environment, i mean, for cheap parts like a chainsaw housing, maybe pour liquid magnesium in an inert environment for a part for the space shuttle, but not chainsaws. i'd guess to melt and pour in an inert environment they'd have to use (relatively) small (comparatively miniscule) batches, very expensive, economically unfeasible. i'd guess there is a (presumably very narrow) temperature range in which magnesium can safely be in a liquid state before it ignites... probably any sharp edges within the crucible could ignite it. but then if it is so tricky to use what economic reason would there ever be for a manufacturer of mass produced items to use it?

b.w.

Reply to
William Wixon

Pete Keillor

Reply to
Peter T. Keillor III

Hello

If you would like to repair any of the aluminum zinc alloys then check out this filler metal

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It appears to be only available in stick form suitable for TIG or Oxyfuel only. I have used it several times and it works quite well.

John

Reply to
john noon

Yahoo has a casting group called hobbicast. You can go to

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and read some of their messages. You can also subscribe to the list and have the messages mailed to you. They sometimes talk about the types of sand, grease ?, etc. needed to the job right the first time.

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HotRod wrote:

Reply to
Al Patrick

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