Arc Air Gouging

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Russ Hanscom
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Arc Air Gouging

Post by Russ Hanscom »

I have a lot of 1/2" thick plate to weld up, the parts come with square edges so some form of edge preparation will be needed.

I was thinking that if two related parts were placed with the mating edge together, the joint could be gouged out in preparation for welding.

Can someone suggest a reference that tell how large a groove results from what sized carbon? I would be looking for a groove 3/16 to 1/4" deep and a bit wider.

Thanks
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steamin10
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Re: Arc Air Gouging

Post by steamin10 »

Commonly in plate fitups, small parts are ground and larger plates are edged with a machine that is set to take about 2/3 of the thickness by a cutter. ( or half and a flip for two side full pen). Heavy plates are torch trimmed, and scale ground to clean them. This prevents firescale from getting into the weld areas.

I think that gouging the plates will not save time, and actually make the cleaning of the weld area (grinding) more dificult and time consuming.

You answered your own question, as a straight gouge with 1/4 carbon on a good DC machine will give you just about a 1/4 inch plus a little. A little sweep, and you open a bit more. I use up to 3/8 carbons for demolition of things, where a torch is too brutal to save things.. As mentioned, consider a guide, and torch trimming the edges for what you need, especially on straight line edges. The secret is speed and good torch settings, for an even and clean cut. The scale should be loose and just about brush away. (very little grinding).
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
It is not getting caught in the rain, its learning to dance in it. People saying good morning, should have to prove it.
hammermill
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Re: Arc Air Gouging

Post by hammermill »

plasma or torch would be a better way to prep the metal if a posibility, air arc will leave a lot of carbon behind you will have to remove by grinding.

daves on track with the dimensions
redneckalbertan
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Location: South Central Alberta

Re: Arc Air Gouging

Post by redneckalbertan »

If you want to use a gouged to prepare the plates you certainly could. It is noisy, dirty, has a tendency to deposit sparks where you don't want (down the back of your shirt), and did I mention noisy! You do see a u joint, which you would get from the gouger, used a lot in industry for prep on larger plates, read inches thick. In cases like those it is cheeper because less weld material has to be deposited. For 1/2" plate I agree with the previous posters a torch is much easier, quicker, and quieter. Use a piece of heavy flat bar as a straight edge and you will be set, make sure it is heavy enough to resist warping. I did find a picture of a jig to hold your torch head at a predetermined angle that may be handy to make that is below as well as a couple pictures of plate prep. If you need full penetration on 1/2" plate I wild set it up with a 60 degree included angle with a 1/8" gap and 1/8" root face and use a 1/8" welding rod. Preset your plates so they are not straight when tacked up as you weld the plates together they will pull together.

To answer your original question though, the groove will be slightly larger than your gouging rod. Depending how steady you are. I like running hot to gouge I find it works much better than cold. 280ish amps on 3/16" rod is what I do. I had a gouging job in the shop here a month ago and plyed around with air pressure from 50 - 100 psi and found that there is a big difference in performance as you go up in 10 pound increments up to 80 pounds 90 was still better but not as noticeable and 100 was slightly better again but even less noticeable so I used 80 psi for the rest of the job. If you do go with the u joint I would gap it as well at 1/8" and have a 1/8" root face there as well!
Attachments
Jig that may be handy to make.
Jig that may be handy to make.
image.jpg (9.89 KiB) Viewed 4265 times
U joint plate prep.
U joint plate prep.
Bevel plate prep.
Bevel plate prep.
Picture of plate prep.
Picture of plate prep.
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steamin10
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Location: NW Indiana. Close to Lake Michigan S. tip

Re: Arc Air Gouging

Post by steamin10 »

By Golly! 110% of what I tried to explain!

A pic is worth a thousand words, thanks for those.
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
It is not getting caught in the rain, its learning to dance in it. People saying good morning, should have to prove it.
redneckalbertan
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Joined: Thu Nov 01, 2012 10:39 am
Location: South Central Alberta

Re: Arc Air Gouging

Post by redneckalbertan »

steamin10 wrote:By Golly! 110% of what I tried to explain!

A pic is worth a thousand words, thanks for those.
I found them on google!
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