Are SIG aluminium frames weldable?

[Whats-his-name]

Howdo all,

I've tried contacting SIG (US and Germany) but am having trouble so hence this post.

I have a 1997 SIG P228 which has had damage to the trigger guard. I aim to TIG weld it but sadly the aluminium is propriety and therefore I have no idea if the aluminium alloy is the type that is weldable.

Does anyone know if it's weldable, and if so what ali' alloy will make the best filler metal.

Cheers.

 

[Zeke/PA]

Don't even ATTEMPT to try to weld it".
Look at every OTHER alternatives !
First off, the part is probably CAST aluminum that is not exactly Welder friendly by ANY means.
I can elaborate!

 

[19-3Ben]

I've tried contacting SIG (US and Germany) but am having trouble so hence this post.

For liability reasons, I would be incredibly surprised if Sig gave you any adivce that might lead to you welding part of a firearm.

I wish I could help you wrt the welding. I just don't know. But if it's a stress part I'd say send it back to Sig or send it to a qualified gun smith. Welding part of a gun yourself is a wicked bad idea.

 

[Whats-his-name]

I wish I could help you wrt the welding. I just don't know. But if it's a stress part I'd say send it back to Sig or send it to a qualified gun smith. Welding part of a gun yourself is a wicked bad idea.

Thanks for your replies.

Nah, not a stress part thankfully.

I'm also a pro' TIG welder and have worked on pistols/rifles with no issue and produce stunning results (yep, I'm that good [he says humbly]).

I won't have an issue with the trigger guard but I need to know if this is the type of aluminium alloy that is weldable, i.e., has anyone tried it? If it's not and/or it's cast then there'll be trouble in which case I won't bother.

 

[drsfmd]

Check with your local recycling yards. Some have a little machine that uses a laser to burn a spot to identify the alloy. Not sure what the machine is called.

 

[KansasSasquatch]

There are products that allow you to weld just about any alloy, even if its cast. I used to have a contact for these specialty products but can no longer find it. You should b able to find them if you google hard enough.

 

[Whats-his-name]

Check with your local recycling yards. Some have a little machine that uses a laser to burn a spot to identify the alloy. Not sure what the machine is called.

That's a good point. I'll hunt around.

There are products that allow you to weld just about any alloy, even if its cast. I used to have a contact for these specialty products but can no longer find it. You should b able to find them if you google hard enough.

Yep, I know the ones you mean. I have a load of Durafix aluminium welding rods which will do the job but it means using a gas source to melt the rod and it's a lot less precise (read messier) than a TIG weld. However, if it's my only alternative then so be it.

 

[Seven High]

I would suggest that you go to the Sig Forum to their gunsmithing area and ask that question.

 

[12131]

I would suggest that you go to the Sig Forum to their gumsmithing area and ask that question.

And they'll probably bop you on the head for even thinking of doing such a thing.

 

[Rinspeed]

Let's see a picture of the damage.

 

[The Lone Haranguer]

Just how bad is the damage? If it is just a large nick or chunk out of the trigger guard but it is still intact, I would just live with it and not weld anything. If there are sharp edges that would cut your finger or holster, take a needle file or something and smooth them up. If it is bent or fractured so badly that trigger movement is compromised or you can't get your finger through, get a new frame, if possible or cost-effective (i.e., ~50% or less the cost of a new gun). Even TIG welding and liberal use of heat control paste isn't going to save the frame finish (a thick anodizing).

 

[Robbins290]

if it is metal. it's weld able. I'm a welder by trade. I would never weld on a firearm. I would take it to a gunsmith. I have mig'ed and tig'ed flash hiders and muzzle breaks on barralls. and it don't look good at all. a smith knows how to make it look pretty

 

[dogmush]

On the triggerguard, there are some rods out there that join Al at MAPP gas temperatures. Basiclly fancy solder. It would be easier on the finish, and the rest of the frame. You'd still need to refinish the joint somehow.

 

[JDBoardman]

It is highly unlikely that the SIG frame is cast; most likely it is a forging that was then machined into final shape. Cast aluminum does not anodize uniformly and the inherent material properties of cast aluminum do not lend themselves to use as a pistol frame.

Your first problem is that the surfaces are anodized. This is a thick aluminum oxide and, unless removed, will require excessive heat. The base metal will likely melt before the anodize film lets go. If you are a welder, you understand that one of the difficulties of welding aluminum, is getting through the naturally occurring oxide film; this is why it is almost impossible to solder aluminum. You can remove the anodize from the welding area mechanically, using a file or a scraper (don't use abrasives, the particles will embed in the aluminum and screw up your weld. You can also remove the anodize with a sodium hydroxide (lye) solution locally applied to the area you wish to weld. This is probably the best way, but it is extremely important thatyou control both the location and how long it is applied.

Remember also that the completed weld will be, metallurgically, a casting. The high residual stresses in the weld can cause cracking at the edge if the weld (heat affected zone, or HAZ) unless the stresses are controlled by a localized post-welding heat treatment - perhaps by a controlled slow cooldown.

If you can describe what the area needing weld repair is like, perhaps we can give further advice as to how to proceed.

John

 

[918v]

How are you going go refinish it? It's prolly cheaper and less of a headache to have Sig replace the frame.

 

[TrueTexan]

You can see if Sig will replace it but they may not as that is part of the receiver and has the serial number of the gun .

Have you called sig customer service here in the U S?

 

[Whats-his-name]

Thanks everyone for their input - and sorry for posting the thread in the wrong section.

The damage to the trigger guard was quite severe - bottom fore-end snapped and bent upwards and no doubt there will be some stress fracturing in there somewhere. Don't ask how it happened as it was on lone to a friend suffice to say it wasn't an issue with the pistol itself!

I used to be an armourer for the military so know my way around repairs, etc., - I just never knew what type of aluminium SIG used for their frames.

Your first problem is that the surfaces are anodized. This is a thick aluminum oxide and, unless removed, will require excessive heat. The base metal will likely melt before the anodize film lets go. If you are a welder, you understand that one of the difficulties of welding aluminum, is getting through the naturally occurring oxide film; this is why it is almost impossible to solder aluminum. You can remove the anodize from the welding area mechanically, using a file or a scraper (don't use abrasives, the particles will embed in the aluminum and screw up your weld. You can also remove the anodize with a sodium hydroxide (lye) solution locally applied to the area you wish to weld. This is probably the best way, but it is extremely important thatyou control both the location and how long it is applied.

Remember also that the completed weld will be, metallurgically, a casting. The high residual stresses in the weld can cause cracking at the edge if the weld (heat affected zone, or HAZ) unless the stresses are controlled by a localized post-welding heat treatment - perhaps by a controlled slow cooldown.

Yep, that was pretty much my thinking. Thanks John. I would be going that way (perhaps re-andodizing the whole frame) but SIG Germany e-mailed me back about my query.

The upshot of it is that the frame cannot be welded and they say to replace it. With this in mind I shall replace the frame and not bother trying to see if anything can be done, even if it's a non-stress part of the frame. Thankfully it won't be at my cost as the chap who caused the damage is happy to pay for his misdeed. Shame it was just the P220 that SIG made with a steel frame. I'm one of those who likes to repair (and improve) getting a sense of money saved and, above all, experience and knowledge gained.

Thanks again all for chipping in with your thoughts and advice - very much appreciated. THR at its best.

Take care.
Steve.

 

[ApacheCoTodd]

Still no photo?

What you describe leads a fella to wonder what other areas of the firearm were stressed.

How about a photo?

 

[BADUNAME30]

Since a refinsh job is in order any how...why no just mix some JB Weld and repair it that way.
Seems like a no brainer fix to me.
I have used this stuff for repairs that would boggle the mind.
The key to it is to not use it as a 'glue' but a filler. Remove some metal between parts to be bonded and of course, you know, CLEAN is required.

 

[lathedog]

This seems like one of those questions, where if you are asking people on the internet, you should not do it. Go buy a new gun.

If you were a good enough welder, you would have just done it and be back on the line shooting.

Apologies if I sound like a jerk as I do not intend to be dismissive.