Mark Allanson
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| posted on 13/11/04 at 10:48 PM |
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quote:
Originally posted by gazza285
That's 15 years of pipe welding experience up the spout then.
This isn't pipe welding, its chassis welding. I was a pro pipe welder, and not normally one to quote credentials, but I have ASME IX in 1-6G and
BS4872 in just about every other form of welding except MIG braze, but I am waiting the results on a recent test (confident).
The difference is that any distortion in pipe will be on the last weld in the pipe, I used to use blade wedges and chalk (yes, Rorty chalk! to give
1" warning of a wedge, you cannot see them coming up when using EW13's and a very tight arc on low hydrogen)
Thin wall tube needs to be touching, at the very least, and usually cut long and beaten into place to make allowances for the contraction, you need to
be in control of the distortion and use it to do what you want rather than be a victim to it. You are going to loose about 25% of the fillet width as
the metal cools - so make allowances
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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cassidym
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| posted on 13/11/04 at 10:58 PM |
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Mark, for a newbie's education - how do you make allowance for the contraction?
Currently distortion is my main enemy and I still have'nt got that intuitive understanding of distortion and how to manage it properly.
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Mark Allanson
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| posted on 13/11/04 at 11:27 PM |
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After I had fully welded my chassis, I had 3mm lift on the right and 4mm on the left, I cut the (quick look in book!) TR tubes 2 and 3mm too long and
wedged them in after raising the chassis on spare bits of rhs/erw. This dipped the chassis by 1mm on both sides. After welding it was true on both
sides. If the chassis had drooped, I would have cut them short and let the distortion draw the chassis up.
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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Rorty
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| posted on 14/11/04 at 01:53 AM |
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quote:
Originally posted by Mark Allanson
... I used to use blade wedges and chalk (yes, Rorty chalk! ...)
Sorry Chalky!
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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cassidym
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| posted on 14/11/04 at 11:03 AM |
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My accuracy greatly improved when I started using a scribe.
A problem still is when I want to draw a line across all faces of the tube. The round edges of the corners throws me off by a .05 to 1mm which I find
unacceptable.
I've tried diff. techniques to extend the line but it's still a 50/50 type of affair.
Thanx guys.
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pintoman
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| posted on 14/11/04 at 04:09 PM |
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quote:
Originally posted by cassidym
A problem still is when I want to draw a line across all faces of the tube. The round edges of the corners throws me off by a .05 to 1mm which I find
unacceptable.
cut a peice of 1" angle iron
locate on one scribe mark and mark off other edge
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cassidym
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| posted on 14/11/04 at 04:32 PM |
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Why do I suddenly feel so stupid! zaz
Very, very obvious solution - thanx pintoman. vc
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cassidym
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| posted on 14/11/04 at 05:45 PM |
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Sorry bout the extra words at the end of each sentence.
No it's not a foreign language - it was my 1 year old son who helped me with my reply, little bugger.
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Peteff
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| posted on 14/11/04 at 06:19 PM |
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I know what you mean
I had 3 year old grandson helping me modify an airbox the other day. His solution to what to cut it with, some scissors .
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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JoelP
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| posted on 14/11/04 at 06:28 PM |
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quote:
Originally posted by cassidym
Sorry bout the extra words at the end of each sentence.
i didnt even notice them. hgd
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