Ask your WELDING questions here.

[ivantheterrible]

thanks for all of the replies.

The problem with grinding is that the metal is very thin, (old roofing tin) and I'm afraid I can easily take off more metal then I can afford.

This is for a sculpture I'm working on. I'm planning on cutting out the shapes, shaping them on the english wheel, then attaching them together. I'd love to completely weld every seam, but it'll more likely be several tacks.

if it matters, I'm using oxy / acet for the work.

[tbarstow]

Originally Posted by ivantheterrible

thanks for all of the replies.

The problem with grinding is that the metal is very thin, (old roofing tin) and I'm afraid I can easily take off more metal then I can afford.

This is for a sculpture I'm working on. I'm planning on cutting out the shapes, shaping them on the english wheel, then attaching them together. I'd love to completely weld every seam, but it'll more likely be several tacks.

if it matters, I'm using oxy / acet for the work.

Use a respirator with zinc cartridges and use a wire wheel to remove the zinc. Since the material is thin, try tacking them to a backing plate.

[victor441]

is proportional to the change in degrees kelvin, so the pressure increase for a gas bottle going say from 70F to 120F is not all that great... i.e. P1/T1 = P2/T2 or P2= (P1*T2)/T1 P2= P1 * (322/294) so P2 is about 10% higher
http://en.wikipedia.org/wiki/Gas_laws

on a unrelated welding topic just made a rack out of 1/2" tubing (not finished yet in the photo) and discovered a 12" round file is just the right size to notch the tubes and works quickly if the notch is started w/ an angle grinder...have a hole saw type notcher but AFAIK hole saws are only available as small as 3/4"

[JAFO]

Very nicely done. What process did you use, and and how did you make the bends? Also what kind of tubing?

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[victor441]

Originally Posted by JAFO

Very nicely done. What process did you use, and and how did you make the bends? Also what kind of tubing?

Sent from my MB886 using Xparent Green Tapatalk 2

Thanks! I used MIG to weld and the tubing is 1/2" 16ga ERW, cheap and easy to find, Home Depot, Tractor Supply, etc carry short lengths that are overpriced....much cheaper to buy a 20' stick from a steel supplier. I packed the tube with sand (MUST be completely dry or a steam explosion is possible), heated sections with a MAP torch, then bent them around a big socket clamped in my vice...made a template out of coathanger wire first to get the bends right.
FWIW there is a good article on sand bending at http://www.rorty-design.com/content/sand_bending.htm
also at http://www.v-eight.com/tech_forum/viewtopic.php?t=203

[JAFO]

Damn! Great idea, will have to test this out sometime.

I remember years ago going roundabout with one of the Senior 'engineers' the about why we were not getting good bends in our network equipment conduit, they were trying to use a pipe bender and wouldn't believe we needed to pack the tube with sand. They're out of business now, for some reason ;-)

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[fxstbiluigi]

Originally Posted by JAFO

Damn! Great idea, will have to test this out sometime.

I remember years ago going roundabout with one of the Senior 'engineers' the about why we were not getting good bends in our network equipment conduit, they were trying to use a pipe bender and wouldn't believe we needed to pack the tube with sand. They're out of business now, for some reason ;-)

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HAHAhaaahaaha about a year or so ago someone was wondering how to bend pipe/tubing and I suggested packing it with sand, even went into some detail, about how to do that. I GOT crusified by all the self proclaimed experts that know everything about metal fabrication.

[fxstbiluigi]

Originally Posted by ivantheterrible

Can I get good results by brushing the acid on the areas to be welded? I think the size of the pieces to be welded might make finding a large enough container to soak them in difficult.

thanks again!

If you are that worried about zinc poisining and using acid to clean the metal why not buy a 4' or 5' x10' sheet of 16 or 18 ga metal that hasen't been galv'ed. It can't be that expensive and you'll save money and time by not halving to mess with the acid and clean-up after.

[ivantheterrible]

actually, the finished project will be out of 16 gauge steel, I mostly want to use the tin roofing for the model and to work out some of the kinks.
Anyway, i found a suitable container, bought some muriatic acid, and it worked great. thanks for all the replies and hopefully I'll have something to show soon.

[KTM640Dakar]

Cross Country Pipeline adventure.

http://www.youtube.com/watch?v=J-x4U...e_gdata_player

[Pago Cruiser]

Have a late model XR1200 Sportster converted to a dual dual purpose hack. Lots of fun off-road, but I gotta start buying clutches by the 6-pack...Done all I can with countershaft and rear wheel sprockets. Need to work on crank and clutch basket sprocket sizing.

Bummer for me: While the XR primary system (using a 3 row chain) is pretty much a clone of a Buell XB, NO ONE makes crank sprockets other than stock 34T (US) or 38T (Europe) for the XR, and a 35 is available for the Buell.

I figure a 30T would be just about right. But the only way I can see to do it is to get a 30T made for an earlier Sportster, and then weld/machine a new inner spline hub from an XR donor sprocket. While I have a Miller MIG and putz with little stuff like saddlebag mounts, my skills mainly consist of being able to burn a hole in just about anything...

All I am looking to find out is: Is this project doable? Welding hardened steel used in this stressed rotational/shear environment? I assume some pre and maybe post heat treatment would be required? Or should I be looking for a machinist to make me something from scratch?

Thanks in advance.

[Twin-shocker]

Thats certainly possible. You will need to get the donor parts accurately machined, ideally with some kind of register so they fit together perfectly, then TIG weld them together. Forget about doing the job at home with a small MIG set, as failure or sprocket not running true is very likely if you try this.

[kirkster70]

Originally Posted by ivantheterrible

thanks for all of the replies.

The problem with grinding is that the metal is very thin, (old roofing tin) and I'm afraid I can easily take off more metal then I can afford.

This is for a sculpture I'm working on. I'm planning on cutting out the shapes, shaping them on the english wheel, then attaching them together. I'd love to completely weld every seam, but it'll more likely be several tacks.

if it matters, I'm using oxy / acet for the work.

Please post some photos. I'm very interested to see your scultpture.

[Pago Cruiser]

Thanks Twin Shocker. I just wanted to make sure it was possible before I go down this path. Now I just need to find a machinist and a welder who know their stuff... have not been to this side of the forum much. Anybody here do custom work like this?

[Twin-shocker]

Try and find someone who can both machine and weld the sprocket. Easy enough here in the UK, but might be more difficult in the US though.