Thread: Soldering aluminium

As far as I know it’s just a high zinc pot metal. The real secret is breaking through the oxide layer on the aluminium and not overheating things. I’ve used them before when the job wasn’t critical or when I knew I’d overheat things with the tig. I keep some in the car, boat and caravan with a blowtorch. Kinda like metallic duct tape. Never the right tool, but sometimes the right tool is the one you have that will get it done.

Hi Phil,

All the holes on the '81ish body on my POS were made to disappear using fibreglass with epoxy resin.

That includes where the repeater lamps were on the front quarter panels (they had none in 74) and a 3" hole in the right rear quarter where the lpg filler was. All was done in situ.

I'd take pics, but there's nothing to see..........might as well be virgin aluminium.

Method: sand the area back to bare metal where you want the glass to stick with no finer than 60 grit, Over the lpg hole I went out to about an inch outside the hole.

Tap in the area you've sanded with what ever you fancy around the hole, blending it towards normal level at the edge of where you've sanded.

The only epoxy I use for this sort of stuff is West System, with a fast or medium hardener.

The only glass I use for this sort of stuff is 4 or 6 oz woven rovings (surfboard glass). Do not use chopped strand mat.

You'll need a 1" brush and a small aluminium ribbed roller and some cardboard and acetone.

Place the cardboard on the ground, cut pieces of glass the right size and place on the cardboard up to 3 layers thick, mix some resin accurately and wet out your patches using the brush. go back and forth over the roller on the patches till the glass is clear and there no all bubbles.

Big holes can be glassed by supporting the glass using tape behind the panel.tempooarily if you have access. Masking tape or Aldi cloth tape.

Lightly paint the areas you've sanded with resin and pick up and place the wetted patches over the holes till you've filled the indentation. Use the roller to remove any excess resin.

Clean brush and roller in acetone after getting as much resin off then with a rag or similar.

When the glass has gone hard just sand off the excess so you have a finish a tiny bit lower than the bodywork.

The rest of the process is just normal refinishing, an epoxy body filler is much better than normal bog.

This method works because epoxy has a much stronger bond to aluminium (or anything else) than polyester resin and it remains very slightly flexible.

I've been using fibreglass professionally for 50 years.

David L

This is great news. I purchased one of these soldering kits to years ago to fix up Citroen DS bonnets with .... One day I'll get to it .... I haven't managed too yet In this case they split at the tip of the bonnet, so I'd be trying to solder up the cracks, then solder in some extra layers of aluminium sheet behind the area to brace it up.

You couldn't really use fiberglass/bog/metal filler or anything like that in this case, as its a flex area and would crack.

This is what the RHF guard looked like.
4CAE8510-1382-4BAA-9644-21CB6C34BA0A.jpg
I used a Dremel to grind off the old cracked welds and then used CLR and a brass wire brush to clean the surface.
A bit of heat and the “solder” stick and presto.
21671C32-A940-4AE8-B063-57DC5B32100B.jpg
Now I have a nice solid front guard.

However, I decided not to solder the holes in the drivers door because I discovered how much aluminium expands when heated while trying to shrink a “stretched” area of a back mud guard.
So, I drilled all of the holes slightly bigger to clean them out, countersunk them and then ran whatever size tap would suit through them.
F570EB3C-BEBC-4BC4-9B8C-2A4FDFA090BC.jpg
I then filled each of the holes with JB Weld (had to do it in a couple of steps as the JB Weld is relatively thin).
The drilling and tapping was to provide as much surface area as possible for the JB Weld to adhere to.
0513AEBD-91B3-4063-8F74-071F30D26E87.jpg
And when sanded off.
FA55C448-5DAA-474A-A7AC-59A7C788F7B1.jpg

Phil

Originally Posted by DoubleChevron

This is great news. I purchased one of these soldering kits to years ago to fix up Citroen DS bonnets with .... One day I'll get to it .... I haven't managed too yet :

As did I

Have you seen the Muggy Weld products?
They may suit your instruments too, John.

Originally Posted by Phil 850

This is what the RHF guard looked like.
4CAE8510-1382-4BAA-9644-21CB6C34BA0A.jpg
I used a Dremel to grind off the old cracked welds and then used CLR and a brass wire brush to clean the surface.
A bit of heat and the “solder” stick and presto.
21671C32-A940-4AE8-B063-57DC5B32100B.jpg
Now I have a nice solid front guard.

However, I decided not to solder the holes in the drivers door because I discovered how much aluminium expands when heated while trying to shrink a “stretched” area of a back mud guard.
So, I drilled all of the holes slightly bigger to clean them out, countersunk them and then ran whatever size tap would suit through them.
F570EB3C-BEBC-4BC4-9B8C-2A4FDFA090BC.jpg
I then filled each of the holes with JB Weld (had to do it in a couple of steps as the JB Weld is relatively thin).
The drilling and tapping was to provide as much surface area as possible for the JB Weld to adhere to.
0513AEBD-91B3-4063-8F74-071F30D26E87.jpg
And when sanded offFA55C448-5DAA-474A-A7AC-59A7C788F7B1.jpg

Phil

That looks to be a pretty good fix to me Do you have any corrosion. I have a tiny bit in the bottom of the drivers door. I have no idea how to fix it as its aluminium and dis-similar metals..... hmmm.... metal would be simple, I'd just zap some fresh metal in there. with aluminium I'm not sure.

seeya
Shane L.