Fao Bygde - Welding

[ToneMonkey]

Alright mate, following on from the other thread, I've started this one so as not to hijack aidlook's.

My problem is that I need to join 2 pieces of steel. 1 piece (side/vertical) is 0.9mm, the other piece (top/horizontal) is 0.7mm thick.

The side is bent and clamped around a curved form. The top then sits on top of it (obviously) to be joined. I can create a lip or teeth in the top and bend it round at 90 degrees if needs be. I'd prefer not to have to, but the option is there if I need it (for example, if welding it isn't suitable and I need to silver solder/braize it).

Obviously I need to limit the amount of distortion that the metal sees to an absolute minimum. The finished weld will also need sanding down to form a nice rounded edge with the top and side.

Also, just to make things difficult, this may be chrome plated. This is done at a fairly high temperature, so if I end up silver soldering it, it would have to be able to stand this temperature.

Any help would be greatly appreciated.

On a lighter note, aren't you a fairly long way north in Sweden? Thought it would be fairly dark up there for long periods at the minute, hence the crack about having enough light to work with. I was born in Sweden but moved away was I was still a nipper so can't remember it. Definately going to be going back at some point over the next couple of years. Been promising myself for ages.

Kaj (very happy because there's probably 3 or 4 people on these boards now who can pronounce his name)

Edited February 4, 2008 by ToneMonkey

[ryanb]

I haven't seen the thread you are referring to ... I take it you are trying to join steel sides and top. Are you building a resonator or something?

Welding material that thin can be done but it is VERY difficult to do well. If you have a really good TIG welding expert around, it would be worth a try. Heat is going to be problematic. I would suggest you either just tack weld it and finish with bronze brazing, or just bronze braze the whole thing to keep the heat lower. That will hold up to the chrome just fine. You still have to be very careful with the heat though to avoid warping the metal too much. If you had a lip on one piece, you could even spot weld them then (again) fill with bronze. Practice on something else first.

[Setch]

Kaj,

If you're making a metal bodied reso, take a look in the MIMF library. This thread:

http://www.mimf.com/library/paulick_build_tricone.htm

Is a very comprehensive account of makng a metal bodied reso, complete with over 100 images. You need to be a MIMF member, and be logged in to see the thread.

[Bygde]

It probably is possible with a MIG-weld with 0.6mm wire, but I strongly suggest that you TIG-weld it. Might look like swiss cheese with a MIG You will probably need to set it up for pulse as well, since you are using very thin materials, and the pulse really helps to keep the edges from melting. Also, slope up is preferable, so you can put the filler in before you destroy the edge (slope up means that the welder starts with low power under X amount of seconds, and then raises it to the amps you have set earlier), and you'll probably want to use very low power.

Sorry if my descriptions are very basic, I don't know how experienced welder you are

As for the twisting of the metal, you can't have too many clamps. Clamp the WHOLE top down, just to be sure, and don't do the whole "seam" at once. Try to weld short distances of maybe 2-3" at the time, and try to switch side to the weld you just did. Bad explanation, I know, but it will reduce distortion a lot if done correctly. What I'm trying to say is basically to always have a weld to counter the pull from the weld that is performed. Also you should remember that as the metal gets hot, it'll melt easier (NOO WAAAY!!). Sounds stupid, but at the thickness you are using, it can be critical to remember so you don't make any nasty holes!

Remeber also that the filler "cools" the weld. ALWAYS use filler at that thickness, since it will be less likely to be a hole if you're using filler rather than just melting without it. One little slip and you can have an ugly hole that will need filling. If the weld is done correctly, grinding will be minimum, and I strongly suggest an air grinder with a sandpaper disc, since you have way better control than your standard electric grinder with those regular discs.

Cut a lot of pieces to practice on, even if it takes 126 pieces to find the right settings on the welder. It is worth the time to do a good setup!

Best of luck!

Haha yeah I'm pretty far north, and it can be really cold and dark here sometimes! Last winter we had -36*C, and needless to say, the couch, tv, chips, and 2L of Coca-Cola felt better than to clear the driveway from snow It's getting brighter though, but at it's peak, the sun rises at about 6-7am I think, and goes down at about 3pm! Where did you live in Sweden?

Edited February 11, 2008 by Bygde

[ToneMonkey]

Sorry about the late reply mate, I'd forgot to pop back into this as I've been soooooo busy lately.

As for welding experiance, then I have a little and I have to say that my TIG welding is much better than my MIG welding (which is odd being that it's much more difficult). I think that might have come from playing the drums so my hands and feet can work independantly of each other. And the fact that the mask I was using for the MIG welding was much too dark

Your descrpitions are pretty good and I followed them fairly well. Some of it I knew and some of it I didn't and will be very handy. So thank you very much.

I used to live in Gislaved and was born in Varnamo. Fairly sure that I also lived in Malmo for a short period, but that could have been before I was born. Sadly I've not been to Sweden since and I would love to go back. Maybe one day I'll get there.