Got any tricks

[Pile Buck]

Sorry for all the newbie questions about aluminum . I have to weld this 1/2-inch, half coupling into my aluminum gas tank this morning. Just a little nervous about screwing up the threads. No real big deal I guess, because I could always run a 1/2-inch pipe tap back down through it . But is there a trick to saving the threads the first time without playing catch up later? I know it would be a bad idea to use some type of lubricant on the threads, because it could leak out and contaminate the weld. What about using Teflon tape, is that a bad idea? Or does one just pray to the welding Gods?

I welded the 2-inch pipe nipple in yesterday with no problems; I only had a 2-inch steel coupling to screw over the threads to keep the nipple from warping, not being familiar with aluminum I figured the threads would gall, but they didn’t! So I was just wondering if you aluminum experts had any tricks to pass along to an old newbie?

[tigman250]

i don't take any precautions to save the threads, i just try to concentrate the majority of the heat to the tank (or backing plate if you choose to use one). it does require some finess to not over heat the coupling but is very doable. it will essentially be a fillet weld so pull your tungsten out about a 1/8" or slightly more and weld it up. the true test will come with the leak check......then we will see if the old dawg learnt a new trick

[KB Fabrications]

Hey Carl, those threads will be fine. Just don't try and thread anything on there until it cools.

[FusionKing]

OK i'll tellyou my exp here. I weld those on a lot. They are not that great IMO.
I feel you would be better off not to have anything installed in it when you weld it. I have tried it both ways and usually it will shrink enuff that when you go to take it out it'll sieze with about a 1/4 turn or less. About any type of lube would melt so thats out. I have not found a good way to stop the shrinking and really feel they should be threaded the first time adter being welded. Just my opinion here not neccessarilly the gospel.
The way I see those installed on pontoons from the factory is they weld them to the panel from the backside on just the edge. I don't get that luxury cause I'm the repair guy after the fact.
I carry the correct pipe tap with me and chase the threads if need be very carefully because it is very easy to get it a fuzz off. Kroil has been kind to me on this.
I prefer using the stamped ones that someone posted a while back on the tank flanges thread from Alegis or someone like that and they look and weld on much better.
Heck looking at your fine work and resourcefullness I would venture to say that if you only needed one you could build/make a MUCH better fitting from a piece of 3/8th or 1/4" stock that way the weld is aways from the threads. The only reason people use the pipe is 'cause it is obviously the correct size hole for the tap.
Precisionworks was selling some REALLY NICE ones here on the site and I was planning on getting with him and trying a few...that would be my first personal choice if time wasn't a factor...and I'm sure you are just dying to get welding so my 2nd choice would be make your own and then last would be use that one there. Just know if you put a decent weld like your other flange it's gonna shrink so leave the plug out in my experience. You'll prolly be fine tho.

[Pile Buck]

then we will see if the old dawg learnt a new trick

Oh yeah put a little pressure on the ol dog why don’t cha!

Just don't try and thread anything on there until it cools

Yeah I discovered that real quick when I tried to remove the steel coupling from the 2-inch nipple right after welding it. The thought crossed my mind where is that 48-inch pipe wrench . But that was just a PILE BUCK moment , then the fabricator in me said leave good enough alone

[Pile Buck]

Must have had my tongue on the correct side of my mouth this morning. Man did I ever luck out!


FusionKing, you’ll never know how close I came to going out to the shop, and building my own plug after reading your post! But I’m a very impatient person, most of the time I shoot my self in the foot being that way! But like I said I lucked out!

Talk about wing and prayer, shooting from the hip, or how ever you want to word it. But bottom line I don’t have a clue of what I’m doing.

All I can say is thank you to every one on this board for their patience and understanding in walking me through this learning curve of working with aluminum!

[KB Fabrications]

Nice work Carl!

[Fat-Fab.com]

Very nice job! and you got all worked up. We knew you could do it. And if went the other way you got all of us to tell you how to fix it.


My first foreman told me this
The difference between the great welder good welder and the bad welder is:

The bad welder screws up and everybody knows…
The good welder screws up and only the foreman knows …
The great welder screws up and nobody knows .


Its just metal have fun.

TJ

[Pile Buck]

Nice work Carl!

Thanks Kevin, that’s quite the complement coming from someone with your talent!

My first foreman told me this
The difference between the great welder good welder and the bad welder is:

The bad welder screws up and everybody knows…
The good welder screws up and only the foreman knows …
The great welder screws up and nobody knows.

In my old line of work when driving foundation piles no one could ever see our mistakes, we buried them!
But in marine construction we would pray for only high tides. Harder to see our mistakes at high water, low tide pretty much showed every mistake.

The very last project I actually drove any production piles on, was the Bell Street Pier downtown Seattle. Just about the center of this picture right in front of that big building is a fish viewing area, so the public can stand around and look for fish I guess . The building and the support columns for the overhang of that building are all on 3-pile spray dolphins. So each pile is 120° from each other, on a 4/12 batter. The ones up under the dock / building are picture perfect . The ones out where everybody and their brother can see them looks like a 3rd grader drove them . I hit everything but the kitchen sink while driving them. I was amazed I didn’t break any of these concrete piles.
So if you every make it down to Seattle cruise on by the Bell Street Pier, you can tell everybody, you know the clown who drove those ugly piles

[precisionworks]

Carl,

You made that look too easy Nice work.

[tigman250]

yep i agree Carl, you should be proud, nice looking welds!

[fun4now]

where do you get the lil niples and fitting's??
i got an old aluminum propain tank i'm thinking of turning into my torch cooler tank but the fittings are all the wrong size.
is there a place to get whatever size you want ? i checked the local hardware store but nothing in aluminum.
and nope i got no taps and a lathe to make my own, well i got a small set of taps but not the best, they would be ok to clear a thread but thats about it.
i keep thinking of getting a wood lath and regearing it and adding the nesisary atachments to go steel or aluminum but its probly more truble than its werth, liable to just end up getting hurt

[harcosparky]

i keep thinking of getting a wood lath and regearing it and adding the nesisary atachments to go steel or aluminum but its probly more truble than its werth, liable to just end up getting hurt

I keep looking at an old lathe we have here and thinking the same thing. Been thinking about it for 5 years. You're most likely right in it not being worth the trouble, though I have been real tempted to hang a hunk of aluminum up on it and seeing what happens!

[Pile Buck]

Thanks for the kind words Barry & Craig



James I had the same situation here. Who would have thunk, a city the size of Seattle and you can’t get aluminum pipe fittings ! Something wrong here, I got to do some more checking. Alaskan Copper quoted me $12.?? For a 1 1/2-inch aluminum pipe cap. I got mine from McMaster-Carr for $7.85 But Alaskan Copper doesn't carry any pipe nipples, WTF!

Here is the link to McMaster-Carr


http://www.mcmaster.com/

[fun4now]

harcosparky
i think the biggest problem would be in the mounting of the bits. regearing it should not be too big of a deal but the cutting tips are night and day different, with steel they have to be mounted on a moveable base that can be ajusted by tinny amounts at a time and it has to be 100% securly mounted. if its not and itbends a little it will bind and then all **** will break loose, parts and pices flying every where. probly best to just save up for a little one and find a way to make some $$ with it to get a bigger one if needed.
Pile Buck
holly cow man,$7.85 for one little fitting. thats nuts, talk about robbing you blind.