Needs Pictures: 0
Results 1 to 15 of 17
Thread: How to get square cornered welds
-
6th Apr 2017, 07:59 PM #1Senior Member
- Join Date
- Dec 2012
- Location
- emerald
- Posts
- 161
How to get square cornered welds
Hi guys, I'd like a little advice from the welding gurus here if possible.
I've just finished welding up a wood heater firebox. I put a posting up here in May last year with the details. Yes it's taken me that long to get it done!!
The material is 12mm plate with full open corner welds. I used Kobelco LB52 for the root run and five passes with Ferrocraft 22. It all turned out fine, but I would really like to have a sharper corner with less radius on clean up.
I was thinking of clamping a strip of copper to the side of the weld and have it above the weld by 20mm or so and then doing another run close to the edge and letting the copper act as a dam. I could then grind that weld flush with the top, roll the box 90 degrees and do the same on the other plane. Would this work OK? If I had some copper handy I'd just give it a try, but I'd be interested in hearing what the gurus have to say.
Thanks.
Eric
-
7th Apr 2017, 12:46 PM #2Golden Member
- Join Date
- Sep 2008
- Location
- N/A
- Posts
- 535
I do use copper bars and blocks to form welds but only on thin material. I can't see why it wouldn't work in your situation though. You might need some big blocks of copper ...
-
7th Apr 2017, 01:42 PM #3Golden Member
- Join Date
- Jan 2016
- Location
- Wodonga Vic
- Age
- 38
- Posts
- 633
Sounds like you need a pack of square electrodes
-
7th Apr 2017, 11:06 PM #4Most Valued Member
- Join Date
- May 2011
- Location
- Murray Bridge S Aust.
- Age
- 71
- Posts
- 5,943
Aluminium works well also.
KrynTo grow old is mandatory, growing up is optional.
-
8th Apr 2017, 08:09 PM #5Senior Member
- Join Date
- Dec 2012
- Location
- emerald
- Posts
- 161
Thanks Guys, I can get hold of some 2mm copper sheet to give it a try. Might be a little thin, but I could back it up with some 6mm aluminium that I have on hand. I wouldn't have thought that aluminium in contact with the weld pool would work that well Kryn, what with the low melting point. Wouldn't it contaminate the weld? Have you used this technique? I'd be interested in hearing your experiences with this. I'm certainly no expert.
I love the idea of the square electrodes Nedshead, but the guy at bunnings had never heard of them and recommended that I contact a specialist welding supplier. He was pretty helpful though and also suggested that I could probably make my own. I told him what I was trying to achieve and he suggested that I buy some 4mm key steel, some iron filings and some powdered borax. He even wrote out the recipe on how to mix the iron filings with the borax. I'll give that a try tomorrow and see how we go. Thanks again.
Eric
-
8th Apr 2017, 11:15 PM #6Most Valued Member
- Join Date
- May 2011
- Location
- Murray Bridge S Aust.
- Age
- 71
- Posts
- 5,943
I have used the aluminium on the sides to help build up the weldment, but not to the extent that you're wanting to do. What is normally done is that the welds are built up in layers, one run alongside the next, as in multiple fillet welds, it's not something that's going to be a quick fix. You could tip the box at about a 45 degree angle, and lay the welds down, decreasing in width as you build up, be aware that constant welding at the one edge/corner may cause distortion. There shouldn't be a need for something to go along side of the welds.
KrynTo grow old is mandatory, growing up is optional.
-
9th Apr 2017, 01:29 AM #7Senior Member
- Join Date
- Jul 2013
- Location
- nsw
- Posts
- 256
it seems you only have stick process, so i would run the largest 6013 electrode on the cold side along the edges to build up material. down hill.
grind/machine down to the required sharp radius.
certainly try the copper forms too.
good luck with it!
-
11th Apr 2017, 08:03 PM #8Senior Member
- Join Date
- Dec 2012
- Location
- emerald
- Posts
- 161
Thanks Kryn and meadow street, yes I've done multiple runs and filled the open corners, but I would guess that I'd need another four or five runs to get it to clean up to a sharper corner. I thought that by using something on the side I could reduce the number of runs and also the time in grinding. I'll give it a try at the weekend if it's not raining (I'm doing all this outside)
Eric
-
12th Apr 2017, 10:10 PM #9
The edges can be built with 6012 electrode. Hold the electrode horizontal to the bead and use an extremely short arc. Travel fairly quickly so the arc makes a very small pool and solidifies quickly.
Build the bead up layer by layer to fill the radiused corner.The arc force will push the depositing bead up fairly vertical. Over build it slightly.Two or three passes should be enough.
No need for copper and ali chill bars.
Grahame
-
15th Apr 2017, 07:13 PM #10Senior Member
- Join Date
- Dec 2012
- Location
- emerald
- Posts
- 161
-
2nd Oct 2017, 09:37 PM #11Senior Member
- Join Date
- Dec 2012
- Location
- emerald
- Posts
- 161
Hi Guys, now that winter is over I'm getting back onto the firebox project. The corners turned out great, but it took a lot of runs and grinding back. I've just got to weld the flange onto the firebox now and this part of the project is complete.
There's a couple of spots around the flange that has quite a gap, something like 3mm. Any suggestions on the best way to fill this gap without the weld pulling too much.
thanks.
Eric
grinding backfirebox and bell.jpgfirebox.jpgfirebox and bell2.jpg
-
2nd Oct 2017, 09:46 PM #12Golden Member
- Join Date
- Sep 2008
- Location
- N/A
- Posts
- 535
3mm gap for 12mm material is about what I'd be looking for as a root gap anyway. As a backyard hack, that is. I'm sure there are official guidelines that are more specific.
-
2nd Oct 2017, 09:52 PM #13Most Valued Member
- Join Date
- May 2011
- Location
- Murray Bridge S Aust.
- Age
- 71
- Posts
- 5,943
Hi Eric,
When I get to a situation like that, I use a couple of bits of scrap flat bar made into a cross and a wedge similar to (a) in the attached link.
welding 2.gif
Hope this helps,
KrynTo grow old is mandatory, growing up is optional.
-
3rd Oct 2017, 08:08 PM #14Senior Member
- Join Date
- Dec 2012
- Location
- emerald
- Posts
- 161
-
3rd Oct 2017, 08:10 PM #15Senior Member
- Join Date
- Dec 2012
- Location
- emerald
- Posts
- 161
Similar Threads
-
Need someone to look over my welds
By gazza2009au in forum WELDINGReplies: 22Last Post: 28th Apr 2015, 04:21 PM -
Some welds for you to critique
By Zumanity in forum WELDINGReplies: 20Last Post: 23rd Aug 2014, 11:30 PM -
Square tubing that's not square
By Corgan in forum METALWORK GENERALReplies: 18Last Post: 1st Nov 2011, 09:31 AM -
Pretty welds
By Dave J in forum WELDINGReplies: 32Last Post: 15th Jul 2011, 02:37 PM -
How many welds?
By Single-phase in forum WELDINGReplies: 7Last Post: 24th Oct 2009, 04:23 PM