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gtcway
08-29-2008, 09:27 AM
I have a Thermal Arc 185 tig. I'm interested in trying the bump welding method to get some practice on anodized aluminum pipe. I know I'm about 15-25 amps short of what's recommended but I'd like to give it a try to see what happens.
First, anyone have any idea on how I can wire a push button switch to the TA 185 to replace the pedal?
Second, do you think it will put a heavy strain on the welder to be a maximum amps instantly using the switch?
Thanks

SundownIII
08-29-2008, 10:31 AM
gtcway,

Miller RMS-14 (Momentary-contact switch) should work on your TA185.

There are probably a few "machine smart" guys on here who may be able to tell you how to wire up a simple (less expensive) on/off switch.

To be honest, I think you're going to be taxing your machine a little. Duty cycle at max output is going to be very low. That said, give it a whirl. Be interesting to hear what results you get.

gtcway
08-29-2008, 11:09 AM
Thanks, I'm not looking to build a t-top or anything. Just looking to get a little practice. I would like to get a Dynasty 300/350 but might have to settle on a used syncrowave 250 when I'm ready. Maybe Miller will have a mid range Dynasty when I'm ready.

Broccoli1
08-29-2008, 11:10 AM
Would it be more prudent to remove the Anodize in the area that needs to be welded for this small of a machine?

gtcway
08-29-2008, 11:14 AM
Would it be more prudent to remove the Anodize in the area that needs to be welded for this small of a machine?

Probably, but I'm not looking to weld anything specific. My goal is to learn how to weld using the bump method, or to at least give it a try.

LarryL
08-29-2008, 12:25 PM
gtc, in my opinion "Scott W" is one of the experts on how to use on-off switches with a GTAW welder, especially a Thermal Arc inverter one. Maybe he'll chime in here. :)

By the way, what is "Bump welding method?"

LarryL

B_C
08-29-2008, 01:51 PM
The last thing I want to Tig weld is any aluminum that has been anodized....The stuff is TERRIBLE to weld and breath,,,,not to mention it will look like KAKA....My experience has always been to try and remove as much of the coating as possible and it still welds bad...Why are you selecting anodized aluminum to weld on? Bump welding as you put it is for quick stitches on sheet metal and thin metals....You need the WARM UP with aluminum to get the expansion and set....I have never blasted aluminum from COLD...
and got a good weld...Not saying it isn't done.....Just that I don't see any advantages...

SundownIII
08-29-2008, 06:21 PM
B_C,

Anodized aluminum is tig welded (using a bump method) every day. The bump method was developed by Pipewelders (largest marine tower fabricator in the world) headquartered in Ft. Lauderdale.

A very detailed article appeared in metalforming magazine about the process and how it evolved.

There is a link on the Hobart board under General Welding (Thanks SundownIII).

After you've read the article, I think you'll have a better understanding of where I'm coming from.

Anodized aluminum towers are used on a high percentage of sportfishing boats over 30'. The anodizing provides protection from the salt water. These towers are fabricated without removing the anodizing and the welds themselves are painted to provide protection. The towers are too large to anodize after construction.

gtcway
08-30-2008, 11:15 PM
Anyone have any idea on rigging a switch on the Thermal Arc? I can get a push button momentary switch and connect it, just need to know where to hook it up? (if it's that simple).

pipedreamer
08-31-2008, 08:08 PM
I have a Thermal Arc 185 tig. I'm interested in trying the bump welding method to get some practice on anodized aluminum pipe. I know I'm about 15-25 amps short of what's recommended but I'd like to give it a try to see what happens.
First, anyone have any idea on how I can wire a push button switch to the TA 185 to replace the pedal?
Second, do you think it will put a heavy strain on the welder to be a maximum amps instantly using the switch?
Thanks

gtcway
If you have a 14 pin plug on your machine where your footpedal goes, you should be able to use Miller's remote switch stock#187208 costs $152.00.

http://www.millerwelds.com/products/accessories/remote_controls/

Or you can make your own for about $75.00. You will need an amphenol plug
with the same pins as on your machine where you plug in your foot pedal, a length of 2 conductor wire a little longer than your torch cable and a momentary button switch. You can get the plug at SSC Controls along with the cable.
http://www.ssccontrols.com/homepage-connector.htm

The people at SSC will be able to tell you what 2 pins to use on the plug.
I say that you might be able to use Miller's remote switch because I have
the thermal arc 300tsw and I use my Miller foot pedal and remote switch on it. I found that out from SSC when I questioned them on whether it would fit or not. They informed me they were the ones who made the OEM footpedals
for thermal arc.

I have been welding anodized pipe for 27 yrs. It's very easy just takes a little practice. You want 1/8 pure tungsten, #6 cup ,3/32 5356 wire, 145 amps
using a helium argon mix 75% helium 25% argon. Your lws should have the gas mix, we call it hot gas. If you use staight argon you will need about 250 amps. As far as welding anodized pipe, the easiest way I can tell you is keep your tungsten perpendicular to the joint. Hit the button rapidly 3 to 5 times. I call it pulse (bump). Anodize coating is non conductive. If you only arc on one side of the pipe, direct the torch to the other side, rapidly pulse 2 or 3 more times. You should now have an arc pit on the other side of the joint. Now return the torch to the center of the joint again, pulse another 2 or so times a little slower so you can put some heat into the pipe. Dip your wire into the puddle, advance pulse and dip. Now just keep going.

When you complete the joint, you can run a heat pass. That's when you go back over your weld not using any wire. The purpose of this is to float the little black anodize flecks to the outside of the puddle and even up your weld bead. Delay your pulse until the puddle is the size of the one previous. That's where the stack of dimes comes in or the row of nickles. I hope this helps you get started but remember, this is not gospel. Change technique to whatever suits you. I have been lurking on welding forums for a long time because typing sux for me. I started this answer last night and my wife just now finished editing. Haha.

gtcway
08-31-2008, 09:58 PM
Thanks pipedreamer for taking the time to post the information. I remember what it was like to take hours to type a couple paragraphs. Now I can type faster that I can think of what to write:)
The gas might be a problem. Being in the Bahamas, I don't have a LWS, it's an automotive repair shop that ships tanks off to another island to have them filled. They can probably order one for me but I doubt they will know what I'm talking about when I ask.
About the pure tungsten, I assume your thermal arc 300tsw is an inverter like my 185. Do you ball the tungsten?
One more thing, what do you set the balance to for the cleaning action?

SundownIII
09-01-2008, 12:28 AM
Pipedreamer,

Appreciate your insight and effort to post. Thanks to your wife also, more on here could use like assistance.

The "hot gas" is something I have not tried with tig on anodized aluminum. I'll have to try it. I have used a similar helium/argon mix when mig welding heavy aluminum. The helium does get a little pricy though. I can see where it "may" help boost the performance of a smaller output tig.

I did have a couple of comments about other things in your posting. If you're still using pure tungsten in an inverter, you're living way in the past. I'd recommend a 2% Lanthanated tungsten for that machine. Try it, I think you'll like what you find. I've gotten away from using pure, even on a transformer machine.

Additionally, your recommendation about a second pass without filler, goes against everything I've ever been taught about welding anodized aluminum. All my mentors, and these are some of the best marine fabricators out there, have always insisted that single pass is the "only" way to weld anodized aluminum. Their feelings and mine, based on similar experience to your's, is that the second pass makes the material more brittle and subject to cracking. This is what makes repairing a weld failure on a tower so difficult. The repair may be great, but ultimate failure in the HAZ is much more likely. This is because the repair was in reality a "second pass" at the base material.

As you so accurately stated, everyone will develop their own little technique in doing anodized aluminum welding, but single pass is something that was "beat into my head many moons ago".

Thanks for posting. Be good to see more of you on the boards. Perfect typing not required. Common sense and demonstrated experience appreciated.

pipedreamer
09-01-2008, 08:46 AM
Thanks pipedreamer for taking the time to post the information. I remember what it was like to take hours to type a couple paragraphs. Now I can type faster that I can think of what to write:)
The gas might be a problem. Being in the Bahamas, I don't have a LWS, it's an automotive repair shop that ships tanks off to another island to have them filled. They can probably order one for me but I doubt they will know what I'm talking about when I ask.

If you can get yourself on a bottle of helium and 2 regulators you can mix it yourself. Just get yourself a brass y connection. I like the one with 2 shut off valves so you can shut off the helium when you don't need it.



About the pure tungsten, I assume your thermal arc 300tsw is an inverter like my 185.

Yes it is. Also, is the 185 a square wave machine? That makes all the difference in the world.


Do you ball the tungsten?

This is a question on another board that started a feud. Let me start out by saying early in my career as a welder I worked for General Dynamics the Electric Boat Division building submarines. I had a 2 day in house training on sharpening tungsten. In the shipyard yes, you ball the tungsten. In my shop, no on anodized pipe. If the tungsten is new, I ease the edge of the painted side to make it easier to enter the collet. On a used piece of tungsten I belt sand it, laying it almost flat on the sander bed to remove any aluminum. Then lift it a little while rotating it to make the tip slightly conical. Then I dress the end square.
I only break the end off when it's split. On dc welding, I grind my tip on a bench grinder, using a pin vice on smaller pieces.


One more thing, what do you set the balance to for the cleaning action?

On my syncrowave machines, it's set between 7 & 8. My thermal arc was very finiky, mainly because the machine was new to me. It is a machine that is dedicated to anodized pipe only, so once I set it I have never moved it. I have to go to the shop today to finish a job for the boat show this weekend I'll check and get back to you.

pipedreamer
09-01-2008, 11:12 AM
Pipedreamer,

Appreciate your insight and effort to post. Thanks to your wife also, more on here could use like assistance.

[QUOTE]The "hot gas" is something I have not tried with tig on anodized aluminum. I'll have to try it. I have used a similar helium/argon mix when mig welding heavy aluminum. The helium does get a little pricey though. I can see where it "may" help boost the performance of a smaller output tig.
Years ago we only used argon. I was the biggest hold out on mixed gas because of the price. But hot gas and a squarewave machine kicks a$$ on anodized pipe. You don't see all the anodize flecks in the center of the weld bead. It seems to float the flecks to the edges leaving the center shiny like you were welding mill finish. A heat pass cleans this up a little more.


I did have a couple of comments about other things in your posting. If you're still using pure tungsten in an inverter, you're living way in the past. I'd recommend a 2% Lanthanated tungsten for that machine. Try it, I think you'll like what you find. I've gotten away from using pure, even on a transformer machine.

I have many many boxes of tungsten red, green, brown, and 1 orange. If
2% Lanthanated is orange I tried 2 pieces from the box. I think I liked it but it was so long ago I can't remember. But I will try it again and let you know. Thanks. The reason for so much tungsten is, before I got my syncrowave I had a dialarc. There was so much tungsten spitting while welding that every time I ordered wire and gas I ordered a box of tungsten. I haven't ordered tungsten in about 6 Years. I still have at least 12 boxes left of the green. If you are right, what the heck do I do with all that tungsten? **** I just turned 50 I thought I was on the down side.





Additionally, your recommendation about a second pass without filler, goes against everything I've ever been taught about welding anodized aluminum. All my mentors, and these are some of the best marine fabricators out there, have always insisted that single pass is the "only" way to weld anodized aluminum. Their feelings and mine, based on similar experience to your's, is that the second pass makes the material more brittle and subject to cracking. This is what makes repairing a weld failure on a tower so difficult. The repair may be great, but ultimate failure in the HAZ is much more likely. This is because the repair was in reality a "second pass" at the base material.
Yes you are correct I was told the same thing by an engineer. He also said no helium and gave me a laundry list of why not. Hot gas is an industry standard now. As far as weld failure on towers, the man I learned from taught me some of the basic fabrication techniques you don't deviate from in all of your builds. Most of the weld failure is because of harmonics. Trailering a boat with a tower or t-top on it is the worst thing for the structure. Funny thing is when I am called out for a repair, I can pretty much tell you where the cracks are just from looking at the structure. One other thing, when I repair a weld I drill 1/8" holes about 3/16" apart in the center of the weld around the entire joint but not thru the pipe. Then I go back with a 1/4" bit and use the 1/8" holes as a pilot hole to remove the weld. If the crack runs away from the joint, drill the end out then vee out the crack before welding. Then you have to figure out why it broke in the first place... usually a missing stand off or sway brace. 3M 5200 is an absloute must on installation. Many manufacturers skip this because it is so messy and they are not the ones to warranty the top.
I was hired by a tower manufacture in AL to repair their towers here in FL.
The tower was missing a piece of pipe which I had been taught was crucial to the structure. It also was missing 5200.


As you so accurately stated, everyone will develop their own little technique in doing anodized aluminum welding, but single pass is something that was "beat into my head many moons ago".

FWIW I have a very dear friend who has a tower shop in New England. He and I still differ on this. But he swears by hot gas and he also was told it was a no no. LOL
I work by some very simple rules. Build it like you were the one who is buying it and if you over build it, nobody knows. But if you under build, it everybody knows.

I like this board. There are a lot of very talented people on here with a lot of great information.