1919 A4 Forums banner

1 - 20 of 34 Posts

·
Registered
Joined
·
2,336 Posts
Discussion Starter #1
Pirate and others say to use 308 for TIG on the 34 receiver.

My welder uses what he calls "missle rod" which is 309 or 312.

Does it make a difference using 308 vs. this "missle rod"?
 

·
Registered
Joined
·
960 Posts

·
Registered
Joined
·
2,280 Posts
I personally use 308L for welding 304 stainless together. Im sure it works for that too, just wondering how it will blue? J
 

·
Premium Member
Joined
·
6,056 Posts
Chuck you don't want missile rod as it is too hard, the receiver needs to have some flex and give to it don't use stainless rod either as it will not blue or park.
 

·
Registered
Joined
·
4,877 Posts
ER70S is what I would use. Never had an issue with it.
CaptMax
 

·
Registered
Joined
·
4,877 Posts
I've used it on Brens, MG34, SG43, and a couple others and have never had an issue with it.
Unfortunately it won't park or blue like the receivers will, that is what DuraCoat or Dulite is for.
CaptMax
 

·
Registered
Joined
·
2,336 Posts
Discussion Starter #9
Odd then that Pirate and others use 308. Why would they use it if it won't blue or park?

I had a receiver done with missle rod and it rust blued fine.

Is there any soft weld rod that *might* blue OK?

I want mine TIG welded, but the ER70S specs I see say MIG. Comments?
 

·
Registered
Joined
·
735 Posts
I'd rather have a strong and durable weld, than one that takes bluing perfectly, but that's just me. I'm not a welder or anything.
 

·
Registered
Joined
·
799 Posts
I want mine TIG welded, but the ER70S specs I see say MIG. Comments?[/QUOTE]you can buy it in 3 foot lengths, in a 1lb tube for tig or on a spool for mig & if you want you can cut lengths off the spool and use it for tig filler rod! Htps!
 

·
Registered
Joined
·
313 Posts
Er70s-2

The welding/machine shop where I work uses mainly ER70S-2 for our carbon steel Tig welding, and ER70S-6 for short arc (Mig).
Works for us.

Dan
 

·
Registered
Joined
·
330 Posts
weld

ER 70 has a minimum tensile strength of 70000 psi and will park blue may leave a slightly different color than base, 308 and 309 can be used for joining stainless to carbon steel, really doubt the receiver gets anywhere near those kinds of stress. The stainless weld will show up like a zebras stripe.
 

·
Registered
Joined
·
2,336 Posts
Discussion Starter #14
ER 70 has a minimum tensile strength of 70000 psi and will park blue may leave a slightly different color than base, 308 and 309 can be used for joining stainless to carbon steel, really doubt the receiver gets anywhere near those kinds of stress. The stainless weld will show up like a zebras stripe.
I always thought welding was 90% about making perfect fillets until I started researching this. Then I read all about welding racing roll cages and nobody can agree on that. Apparently welding is as much art as science, but the science part is more anecdotal than proof.
 

·
Registered
Joined
·
79 Posts
if it don't hold with 70 S6 you did something wrong 70S6 70000 tensile strength more than enough and can be parked blued or matched . Missile rod what exactly is that? 100/pound 312 no thanks I will pass just, use the 70S6 use care before,during,and after welding it will be perfect .
 

·
Registered
Joined
·
2,280 Posts
Weld joining certain alloys requires specific cleanliness and tempering process to prevent shrinking and stress cracking. Short-arc mig is forgiving and relatively easy but clumsy and kinda messy. Tig is the way to go as long as you have a way to limit your heat input . Welders like to use stainless alloy fillers because they are good at joining dissimilar metals and have low distortion. Also make sure to get a good size filler wire. Dont get talked into .030 or some ****. Use .06 or .09 at least, you're not welding watch parts. J
 

·
Registered
Joined
·
2,336 Posts
Discussion Starter #17
Ignorance is not always bliss, sometimes it can be scary.

I went on Amazon to order some ER70S6 and the description says:

General shop applications with poor fit-up
• Steel castings or forging salvage
• Home projects


Poor fit-up? Salvage?

Wire vs rod: if the semi MG34 mating surfaces have no gap, or let's say less than 1/8" gap, is .09 really needed or is .03 OK then?
 

·
Registered
Joined
·
2,280 Posts
First off let me say this is my opinion based on the type of work I do. When dealing with a gap of any size it is better to let the weld pool swallow the filler as needed than it is to try to feed a too thin wire. Present the filler at the edge of the pool and the melt will draw the filler in while you feed it. A thin filler in a gap requires you to feed the wire quickly, pushing it into the weld pool. I think its harder to keep the temp good when forcing the filler into the gap, plus you jam it into your electrode and poof, gotta stop. J
 

·
Registered
Joined
·
4,704 Posts
Ignorance is not always bliss, sometimes it can be scary.

I went on Amazon to order some ER70S6 and the description says:

General shop applications with poor fit-up
• Steel castings or forging salvage
• Home projects


Poor fit-up? Salvage?

Wire vs rod: if the semi MG34 mating surfaces have no gap, or let's say less than 1/8" gap, is .09 really needed or is .03 OK then?
I have ER70S-2. Says it's PREMIUM filler rod. Works good for me. +2 on heavier rod over thinner.
I'm a ficky pucker, so any gap over 1/16" gets a sliver or plug stuffed in before I even start. Not because I'm a good welder. Quite the opposite, really. I hate blowouts.:(

I'm not saying you should, but it's about all that works for me on gaps. They generally end up bigger if I don't.:jedicrying:
 

·
Registered
Joined
·
330 Posts
weld

Bottom line is if you are not experienced at welding, get it done by a professional. You are risking totally screwing up this mg34, and yes welding is a science and an art. Some of the posts are quite helpful and others are pure guess work. Furthermore if this gun is going to be functional, jigs will be required to hold everything absolutely straight, ALL WELDS will shrink.you can practice on welding some tubing together .good luck.
 
1 - 20 of 34 Posts
Top