Not logged inAmerican Welding Society Forum
Forum AWS Website Help Search Register Login
Up Topic Welding Industry / Welding Fundamentals / Dog and Wedge
- - By aevald (*****) Date 03-30-2015 06:05 Edited 03-30-2015 06:09
Hello everyone, this certainly isn't anything earth shattering, actually, quite the contrary.

Most of us who have been in the trades for any period of time have used this or a variation of it. Often times there are things that don't quite line up and you need a way to bring them into line. Where it is admissable to weld onto the parts that you are working on you can use a "wedge and dog" and bring things into line for tacking and then welding.

Here's a little sketch to hopefully explain this process just a bit. Quite often you can speak to the burn table operator in your shop and get them to cut these parts from scrap skeletons before they are disposed of. For the others, you can simply cut these shapes out from your scrap pieces that you might have laying around in your shops.

After tacking your parts into place you can knock the wedge out of the way and then "bend" the dog over and break the tacks and grind/sand these areas back to an acceptable condition.

Best regards, Allan
Parent - - By aevald (*****) Date 03-30-2015 06:23 Edited 03-30-2015 06:29
Here is another small variation of a similar type of application. This involves a piece of angle iron, pipe, sq. tubing, or a lot of other structural shapes that can be substituted and used in a similar fashion. As before, be sure that the material/project that you are working on allows for this sort of tacking and welding other than the specified welds.

As in my other post, once you have tacked your parts into position simply break off the angle piece and grind/sand to acceptable condition.

Best regards, Allan
Parent - - By aevald (*****) Date 03-30-2015 08:36
Here's another member of the clamp/alignment family. You can part-out some of your old clamps to give them new life or you can sacrifice a new one, or you can also make one from all-thread, coupling nuts, or other nuts and some plate. As with the others, only use this on materials or work where tacking is allowed and then remove and grind as required to bring things back to the correct finished condition. Best regards, Allan
Parent - - By Tyrone (***) Date 03-30-2015 10:39
Thanks for sharing Allan
Used all those tools in my early fitter days. Olde timers passed down the tricks of the trade...


PS - You forgot the 10lb sledge hammer.
Parent - - By welderbrent (*****) Date 03-30-2015 14:27
(10 lb) With 'hot tacks'.

Parent - - By aevald (*****) Date 03-30-2015 16:16
Thanks Brent, I had forgotten to include a little something about "Hot Tacking", I'll have to get on that one as well. Best regards, Allan
Parent - By welderbrent (*****) Date 03-30-2015 16:48
Just don't hit them too hard and too soon.  Let them cool just a touch and then hit them as they continue cooling.  Otherwise not only might you get sprayed with flying molten metal but often the tack will break. 

Better to start where the offset is close and work around.  Don't start in the middle of the area to be faired up because you have to move it too far and will have a problem with the hot tacks wanting to crack. 

Parent - - By aevald (*****) Date 03-30-2015 16:15
Thanks Tyrone, you're certainly right about the "10lb er" and Brent reminded me about the "Hot Tacks". Best regards, Allan
Parent - - By PlasmaHead2 (***) Date 03-30-2015 21:45
Further on the wedges, I have used blocks of wood band-sawed into a wedge to move parts around without marring the material as steel wedges would. Handy for stainless and aluminum.
The wood is semi-sacrificial... It might last a few jobs it might only make it through 1... depends on how much movement is needed.

I have a variation of the hot tack but am lacking the proper means of describing it.... gotta go play in "paint" for a bit...

Thanks again Allan!
Parent - By aevald (*****) Date 03-30-2015 21:49
You bet Clif, and thanks for the "use of wood" comments, definitely good to consider with SS and Aluminum items. Best regards, Allan
Parent - By welderbrent (*****) Date 03-30-2015 14:28
Well done Allan.

It is a sad state when we see fitters and welders trying so hard to accomplish something that is so easy with a simple tool.

He Is In Control, Have a Great Day,  Brent
Parent - - By gndchuck (**) Date 04-02-2015 00:37
used a lot of dogs and wedges and U dogs and bullpins for the underwater stuff, works magic
Parent - - By aevald (*****) Date 04-02-2015 02:51
Hello Charles, glad to hear from you, it's been a while. I hope everything has been going well on your side of the states. Best regards, Allan
Parent - By gndchuck (**) Date 04-10-2015 04:36
doing good, keeping busy
Parent - - By Lawrence (*****) Date 04-02-2015 11:49
I feel like a little kid every time you post...

More Pics...  We all want to see you fab stuff underwater !
Parent - By gndchuck (**) Date 04-10-2015 04:35
will have to go thru my photos to see if I have some, sure I do somewhere
Parent - - By 357max (***) Date 04-06-2015 16:44
The use of hydraulic bottle jacks that work in all positions - horizontal or vertical can be used to spread and/or tighten root openings. Use the same principles of the wedge and dogs but use the jacks with angle, beam or channel and fabricate frames to push or pull for fitups.
Parent - By aevald (*****) Date 04-06-2015 19:27
Hello 357max, do you have any pictures by chance? I believe that I can visualize what you are saying/describing but possibly others can not quite so readily. Thank you and best regards, Allan
Parent - - By Josephp (**) Date 04-08-2015 14:43 Edited 04-08-2015 14:50
FWIW I have used the following tool, the Stronghand Half Clamp for several years, located this six years ago. In the long run it is quick, saves time and money. In my opinion they are worth the cost to purchase. Have half a dozen of them. The pieces of 1 1/2" pipe supplied with the tool is thin wall, I cut myself pieced of heavy wall pipe, i found this better for heavy construction work.



Product information at URL:
Parent - - By Josephp (**) Date 04-08-2015 15:01
Another tool is the Walhonde Top Dawg, review the video below;
Parent - By aevald (*****) Date 04-08-2015 15:20
Hello Josephp, nice stuff, I hadn't seen those particular units before, but I could definitely see how they could be a nice addition to an individual's fitting tools. Thanks for including those here. Best regards, Allan
Parent - - By mwmw (**) Date 04-10-2015 02:00
That a nice tool but i use a DIY one. Its simple to pieces of plate about a 1/4 in from each edge with a piece of bar stock welded at the top of one. Then you just place a c clamp towards the bottom and tighten...brings the plate right together nicely( we do this when splice to plates in the flat for shell prep on pressure vessels)
Parent - - By aevald (*****) Date 04-10-2015 02:57
Hello mwmw, by chance do you have any pictures or sketches to show/illustrate/explain your written description. Would like to ensure that I am understanding what you have described. Thanks for sharing and best regards, Allan
Parent - - By mwmw (**) Date 04-12-2015 03:19


Here you go. Some guys drill holes thru both plates and use a piece of all thread and nuts instead of C- clamp ~~ generally the c clamp will do teh job
Parent - By aevald (*****) Date 04-12-2015 23:48
Thank you for sharing that, I have not seen that particular method. But now I have another choice to add to what I share with others. Greatly appreciated. Best regards, Allan
- - By Alaweldor Date 04-04-2015 22:51
I used all three methods on a daily basis way back when I worked in a tank shop.
Parent - By aevald (*****) Date 04-07-2015 18:06
Thanks for the comments Alaweldor, do you have any things/methods to add to this thread? I, and I'm sure others, are always looking for alternative methods. Thank you and best regards, Allan
Parent - - By mwmw (**) Date 04-10-2015 02:02
Same here- we primarily use dog/wedge and half clamp. While fitting shells on rollers alot of times you can just use a wedge if rolled properly
Parent - By Alaweldor Date 04-14-2015 23:10
You mentioned  joining the different shell sections in the rolls. Sometimes I would weld a piece of scrap on each end of a length of chain,  maybe 12"-18" long. I would tack the ends of the chain on each side of the gap. That would keep the shell sections close together but still gave some slack to work with as I rolled the tank and used the dogs and wedges.
Up Topic Welding Industry / Welding Fundamentals / Dog and Wedge

Powered by mwForum 2.29.2 © 1999-2013 Markus Wichitill