I believe most steel conduit is galvanized. If your's is , be careful welding it, as the burning zinc can give you zinc poisoning. The galvanization (zinc) could also be effecting/contaminating the quality of your welds.
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Welding thin tubing with a HF 125 flux core welder
- Thread starter mickri
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Take the HF mig welding wire and throw it in the trash then go get some Crown Alloys, Weldcote, or Lincoln Electric mig welding wire..... If you try to use the HF wire you will think that mig welding is impossible..... DO NOT WELD GALVANIZED METAL WITHOUT A RESPIRATOR...... You can get metal fume fever from breathing the smoke when welding galvanized or other coatings....
en.m.wikipedia.org
Metal fume fever - Wikipedia
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that all depends upon whether you have sufficient bead upon the outside, there is no real strain in the joint, your not grinding the outside flat again.
As it stands there does not look to be any penetration that is fusing both edges together.
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Why I am going through this is I would like to weld up the exhaust header and tailpipe/muffler on my 66 midget myself instead of taking it to a muffler shop. The outside will be ground for appearance on the header but not on the tailpipe/muffler. I will be welding 1 3/8 OD .065 tubing and 1 7/8 OD .065 tubing. This will be a mostly stock engine and not making any attempt to tune the exhaust piping other than the OD. I will most likely use one of these two designs. Which one will depend on clearance between the #4 tube and the foot well.
I won't get to this project until next spring and plan to spend lots of time practicing this winter. Depending on how the practicing goes will determine if I have to go to a muffler shop or do it my self.
I won't get to this project until next spring and plan to spend lots of time practicing this winter. Depending on how the practicing goes will determine if I have to go to a muffler shop or do it my self.
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Get a mig or tig welder & do it right
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Welding on proper exhaust pipe compared to welding on Galvanized conduit is Not At All a good comparison to practice with IMHO but then again what do I know.
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As I have said before there is no money to buy either a tig or mig welder. The HF 125 is what I've got. And I don't do much welding so the HF 125 suits my needs.
The only reason that I am using the conduit is I had some. Next time I go to town I'll check with the muffler shop to see if they have any scrap that I can have for free or minimal cost.
The only reason that I am using the conduit is I had some. Next time I go to town I'll check with the muffler shop to see if they have any scrap that I can have for free or minimal cost.
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Modding your welder to DCEN shows you're not afraid to tinker with things. I found a web site you might be interested in here. It describes modifying a similar welder to use inert gas. If you already have a bottle and regulator you already could be a long way down that road.
I did the DCEN mod to my HF welder and it definitely improved my welds, although I'm not proud of their appearance. I don't have Argon but I do have a CO2 bottle and regulator (my moniker sort of gives away the why of that) & I've been thinking about trying it to see how it would work.
I did the DCEN mod to my HF welder and it definitely improved my welds, although I'm not proud of their appearance. I don't have Argon but I do have a CO2 bottle and regulator (my moniker sort of gives away the why of that) & I've been thinking about trying it to see how it would work.
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@mickri
That's an excellent and ambitious project!
Since you want/need to stay with the welding process you have then my advice is the smallest diameter quality wire you can find, and practice, practice, practice.
When forced to do something like this I usually find that once I get a little spot deposited, I let off the trigger and let it cool a bit. Then I can come back and add a little more. It really is a patch-work of overlapping tacks. The extra mass of metal heats slower and helps avoid blow-thru. It doesn't look pretty, but can get you out of a tight place. It can also be slow since you'll want to clean/brush off the flux-core slag between tacks.
If you need to continue with galvanized, you can simply soak the pipe ends in a jar of muriatic acid (hydrocloric acid).
I used it to strip the galvanized coating off the ends of some (chain-link) fence posts for a project, it worked faster than I expected and stripped both the inside and outside to the depth that was immersed.
You can find that at pool supply stores, see: https://en.wikipedia.org/wiki/Hydrochloric_acid
Keep it away from your good tools though, just the vapor will rust steel in the same room.
For practice how about picking up some exhaust couplers/adapters at your local auto-parts place.
They would be more representative of the actual work piece. Like these:
But those look galvanized too.........
Best of luck, and please keep posting your progress!
-brino
That's an excellent and ambitious project!
Since you want/need to stay with the welding process you have then my advice is the smallest diameter quality wire you can find, and practice, practice, practice.
When forced to do something like this I usually find that once I get a little spot deposited, I let off the trigger and let it cool a bit. Then I can come back and add a little more. It really is a patch-work of overlapping tacks. The extra mass of metal heats slower and helps avoid blow-thru. It doesn't look pretty, but can get you out of a tight place. It can also be slow since you'll want to clean/brush off the flux-core slag between tacks.
If you need to continue with galvanized, you can simply soak the pipe ends in a jar of muriatic acid (hydrocloric acid).
I used it to strip the galvanized coating off the ends of some (chain-link) fence posts for a project, it worked faster than I expected and stripped both the inside and outside to the depth that was immersed.
You can find that at pool supply stores, see: https://en.wikipedia.org/wiki/Hydrochloric_acid
Keep it away from your good tools though, just the vapor will rust steel in the same room.
For practice how about picking up some exhaust couplers/adapters at your local auto-parts place.
They would be more representative of the actual work piece. Like these:
But those look galvanized too.........
Best of luck, and please keep posting your progress!
-brino
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- Oct 31, 2016
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I am just about out of the HF wire. I have purchased some Lincoln nr211mp wire and should get it next week. Will keep practicing with the HF wire until it is gone. My practice butt joints so far seem to be very strong. Beyond ugly but strong. Will be in town tomorrow and will try to get some scrap exhaust tubing from the muffler shop. There is a small junkyard in town that might also have some scrap exhaust tubing. I'll scrounge something somewhere.
If my exhaust system goes as planned I will only have 3 butt joints. The rest of the joints will be lap joints. A total of 12 joints. I am going to make the flange that goes on the engine out of either 1/2 or 3/8 flat bar. The exhaust ports are a rectangle. 1 1/4" x 1." The common practice is to weld a short piece of tubing that has been pounded to the shape of the port and then weld to that. I am going to machine a 1 3/8 hole 1/4" deep in the flange and then grind the flange to match up to the exhaust port. This will give me a slip joint.
That will make it easier to align the tubes and easier to weld. The collector that I will buy has a similar slip fit where the tubes enter the collector. If I can get the welding dialed in than this a doable project for me.
Thanks for the lead on the mig conversion. I have been to Mike's workshop in the past. Lots of usable info on his site.
If my exhaust system goes as planned I will only have 3 butt joints. The rest of the joints will be lap joints. A total of 12 joints. I am going to make the flange that goes on the engine out of either 1/2 or 3/8 flat bar. The exhaust ports are a rectangle. 1 1/4" x 1." The common practice is to weld a short piece of tubing that has been pounded to the shape of the port and then weld to that. I am going to machine a 1 3/8 hole 1/4" deep in the flange and then grind the flange to match up to the exhaust port. This will give me a slip joint.
That will make it easier to align the tubes and easier to weld. The collector that I will buy has a similar slip fit where the tubes enter the collector. If I can get the welding dialed in than this a doable project for me.
Thanks for the lead on the mig conversion. I have been to Mike's workshop in the past. Lots of usable info on his site.
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