Are stainless mag bodies Tig welded or soldered? --- Got any wisdom 4 me Tom?

[Pneumagger]

I am making a stainless mag-like body (which mounts to a mag rail). It will mostly be produced on a lathe. For the feedneck (whether it be a vertical tube or angel-threaded collar) and the body screw I need some facts on their attachment to a stainless body. The internal dimensions and bores on the body are extremely important as the valve and body are one integrated unit. So conventional welding may be out of line for fear of internal dimension changes. Were the old stainless and cabron steel mag bodies high-temp soldered (aka: brazed) or were they TIG welded with a very low current? Close inspection indicates either a very strong Nickel-silver braze or the best damn TIG weld I ever seen.

--- If I TIG weld to a stainless tube of roughly the dimensions of a ULE breech area (for the feedneck and body screw) will there be appreciable part distortion? (body tube wall thickness in the breech area is rougly 0.2")
--- Will high-temp silver soldering or brazing produce any part distortion?
--- Will high-temp silver soldering or brazing be strong enough for a feedneck or body screw?

[EclipseClassic]

I would imagine they were tig'd, but it could be any number of combinations.

[Pneumagger]

Slow night tonight i guess...

[EclipseClassic]

I know a little about welding. I have few welders, and from the looks of the bodies on my mags they were tig'd. Now, Im talking about the powerfeed tube being tig'd to the body. Im almost 100% sure the PF is tig'd to the body and then grinded to look a bit cleaner. That is my opinion.

[Lenny]

Doc did that once. He silver soldered the new collar on.

[maniacmechanic]

tig or silver ; tig would probley be better you can keep the heat exactly where you want it , to keep the heat from spreading use some type of heat sink : as simple as a wet towel& if your tiging this it does not need to be a full circle weld , tig is total penatration so you can stitch weld it & that will also keep your heat down

[Tao]

The orriginal automag tech video says which welds are used on the mag body. It actually has 3 different ones. Searth the forums for the video or search you tube.

[luke]

So conventional welding may be out of line for fear of internal dimension changes.

Yes



Were the old stainless and cabron steel mag bodies high-temp soldered (aka: brazed)

Silver soldered


or were they TIG welded

No.

I believe I'm the only one T.I.G. welding feed necks.


with a very low current?

Very low, yes. I use .03 tungsten.



Close inspection indicates either a very strong Nickel-silver braze or the best damn TIG weld I ever seen.

AGD uses silver solder. Silver solder is commonly used on stainless steel although it is not as strong a T.I.G. welding.



--- If I TIG weld to a stainless tube of roughly the dimensions of a ULE breech area (for the feedneck and body screw) will there be appreciable part distortion?

This is VERY tricky to get right. The answer is Yes and No. Stainless is known to recover from heat well, meaning it doesn't warp as fast as other material, but it can if too much heat is applied. That is why I use a T.I.G. welder, I can control the amount of heat during the welding process. The process I use to change the feed tubes on mags take quite a long time. Care MUST be taken in order to not over heat the body during welding or cleaning of the weld after word.

There are several other factors. The first is that when welding SS tubing where the inner part of the "tube" must remain unaffected by the weld, the inside must be purged with shielding gas. If you don't the stainless will release carbon (I think it's carbon, it looks like it anyway) that builds up on the underside of the weld. But even purging will not guarantee a perfect weld because that is only part of what can go wrong. Not properly venting the tube (allowing pressure to escape but maintaining some pressure to hold the shielding gas) will blow holes in your welds which makes a HUGE mess on a part that needs to be perfect! One other thing is that if you don't maintain the exact amount of heat during welding the weld can "sag" on the bottom side which of course will cause tolerance issues.

I would advise AGAINST T.I.G. welding for what you are trying to achieve. The AM/MM bodies in reality do not have as tight of a tolerance as you are trying to achieve with your project. BUT, that's not to say that the welding (on a Mag body) doesn't have to be done to the highest quality possible because they can be ruined if you are not careful.

If you consider the AM/MM design, the barrel floats between the o rings that center the barrel in the SS tube. This allows for the slightest amount of warping. Really just enough to do ONE feed tube change. Even done to exacting standards I would have my doubts of doing a feed tube change twice.

Warping is what causes bolt stick on brand new guns right from the AGD factory. That is why Tom suggests that the rear thumb screw is only tightened hand tight. Point is, even brand new tubing is not perfect. I've found that the bolt sticks on the inner ring inside the body. Problem is some are worse than others, add extra heat and it gets worse. I've found a fix for it though. :D

Sorry, I got off on a tangent there, but perhaps it will help some... :)



--- Will high-temp silver soldering or brazing produce any part distortion?

Brazing is out...

There is a trick to silver soldering a part without warping it. The trick is to heat the ENTIRE part/s to the same temperature at the same rate. The trick is the heat your parts in an oven that can reach the proper temperature. As I understand it you would need some kind of a jig fixture to hold the parts in place in the oven.

Prior to putting the parts in your fixture you would apply the flux to the area you want the solder to flow, jig up the part, then wrap the exact amount (diameter of the solder would be crucial) around the feed tube (in this case anyway) and bake!. When the the correct temperatures are reached the solder will melt and be absorbed by the flux. After a cool down you're good to go.

This is just a rough guess of how it is done, but you should get the idea. :)

Also, I don't have any idea if AGD uses this method or not but it is a common technique.


--- Will high-temp silver soldering be enough for a feedneck or body screw?

Well AGD uses it, but their feedtubes have been known to fall off. ;)

[Tym]

They actualy tig weld the feed tube on. All together there are 4 diffrent types of weld on the mainbody.. Watch tom kay's Automag video's on youtube, part 5 of 9 about 3/4 of the way through tells you all about it.

Don't know why someone would think they are the only one who does something... Funny tho. look into it and it turns out that's the way EVERYBODY does it.. lol..

[luke]

They actualy tig weld the feed tube on.

Not true.

Tom states they tack the feed tube on.


Don't know why someone would think they are the only one who does something... Funny tho. look into it and it turns out that's the way EVERYBODY does it.. lol..

Because I have removed around 100 feed tubes in the past 4 years, that's why.

Have you ever seen a feed tube knocked off? I have a dozen times or so. If they were welded that would never happen.

I never saw that video, but you are still incorrect perhaps you should review it again. It is only spot welded to hold it in place for the soldering process. He does indicate that an oven is used for the process as I stated.

I also said I didn't know the EXACT process AGD used, but after seeing that I will say I was not far off. Instead of using a jig they "tack" the parts in place.

And for the record, I've done around 100 feed tube mods and have NEVER encountered a body that was even tacked welded. If I had I would have NOT been able to remove the tubes as I do. I am a welder and do understand the difference between welding and soldering, so arguing will get you nowhere.

I would wager that he either changed the process since the video was made or he misused his terminology to describe the process. Until I can question Tom about the process YOU will not change my mind about the subject.

[Tym]

True it is tacked on then brazed after, but tig welded none the less..
Tacked or not they do tig weld it at the factory... You can just assume he made a mistake, or you can accept the fact that tig welding (spotting or full weld) is not that hard to do on a feed tube. And there is no reason a good welder couldn't tig weld the entire thing..

BTW how do you finnish it after welding it? do you grind/sand the weld clean then blast it with wallnut shells or sand like they do at the factory? That would be cool if you could get it looking stock after.

[luke]

What ever.

[Tym]

Sorry, You must have missed my question. Do you refinish the mainbody after you re-weld it? if so, how? I'm interested in knowing what yeilds the best results on the finnish? Wallnut shell blasting? sand blasting?

Thanks.

[Muzikman]

I don't know how they do it in production. But I know Roman can solder a new feed tube on a body pretty quick. When they were still in their old facility they had a small room (more like a closet) with a vice and jig to hold the body and freed tube.

I had Roman remove a powerfeed tube from an original RT body and solder me on a warp feed tube.

[Pneumagger]

What ever.

L O L

[luke]

Were you able to glean any information from my original post? :)

[Pneumagger]

Were you able to glean any information from my original post? :)
yes, very much so. In fact, I realized what a mess i was getting into and redesigned the machining process to make an integrated feedblock for the neck to thread into. :rofl:

[luke]

Good man!

Can't wait to see what you come up with. :cheers:

[gotboostedvr6]

Good man!

Can't wait to see what you come up with. :cheers:


i knocked off my feed neck today and re soldered it with silver solder, the solder AGD used needed a torch to melt :(

[luke]

i knocked off my feed neck today and re soldered it with silver solder, the solder AGD used needed a torch to melt :(

Yes. if it was welded you could not have melted it with torch. ;)

[Freebird]

hmmmmm

could this be acomplishd with mapp gas
or air/acetylene?
or is a propane torch enough heat?


is brazing 100% out of the question?
ive used braze to join steel in the past, didnt turn out too bad(not stainless)

[gotboostedvr6]

i would just silver solder it... if its not strong enough you can always grind and braze