Standards on filling holes with weld

[franhd]

Hi everyone,

I have a situation where the only way to weld two pieces together while also be self-locating is having holes run through both parts, and have the welder run a pin through both while welding the rest of the edges.
Then I would want the welder to remove the pins after weldment, and fill these holes with weld itself.

To my understanding, it's best to plug weld a hole if there's a backing material, but in the case there isn't, how big is too big of a hole to fill with weld?
The material is AL 5086 for reference.

Is there any kind of standard or guide that explains this?

Thanks!

 

[mfgenggear]

Gp
Hard to say don't know the configuration.
Options
1) add weld tabs with alignment holes
Have match drilled or jig bored for tooling. Then after welding machine off.

2) drill and ream .250 diameter holes
Use for alignment, then plug weld after

 

[3DDave]

They can use a temporary backing plate to retain the weld material

https://www.hobartbrothers.com/reso...ide/weld-preparation-treatments-weld-backing/

 

[MJCronin]

The magical words that you seem not to be using are "plug welds"

Google: AISC AWS rules "plug welds" and see what you get !

Thank God only experienced STEM engineers are getting these important weldment design assignments !

(I also believe that, with a detailed sketch, there may be some alternatives that you didn't consider)

MJCronin
Sr. Process Engineer

 

[desertfox]

Hi franhd
Any chance you can provide a sketch of the configuration?

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[kjoiner]

Can you use Clecos to locate and hold the parts together for welding? If so, you would only have a 1/8" hole to fill. We do that on large sheet metal cabinets we make. We don't to the fabrication, but the holes are in the design per suggestions from the fabricators.

Kyle

 

[Tmoose]

Use aluminum "pins" ?

Then after the edges are welded, finish either with autogenous welding the ends of the pin(s) and holes or use pins slightly shorter than the assembly thickness to permit real "plug welds."

Even with pins installed I think the halves of the welded assembly will likely be found to have shifted a little.
Welding = distortion in my book.

========.
What are the requirements of the finished pin holes? Leak proof, ground flat after welding, or ???

I bet you know details like the thickness of the materials to be welded, required final alignment of some features on the individual castings, weight of the components, whether the components are ruggedly proportioned or dog dishes flipped and welded together to create a tight lipped clam shell, ..?... .

 

[ctopher]

Can you tap the holes, make threaded inserts, then weld in place?

Chris, CSWP
SolidWorks
ctophers home

 

[mfgenggear]

Op
An important procedure regardless of configuration. Is to fit up the welded assembly. Generally some type of fixture or alignment tools, set in place then tack welded in place. Machined parts are easier. Sheet metal are more difficult.
Many times details have to be straightened, presses and formed round, or machined to hold registered surfaces , diameters or edges. Most challenging project have been assemblies requiring high or low temperture oven braze. All details require a close gap to make the braze filler to flow all details have to be fit up , tac welded in place with fixtures.