looking for very basic weld info

[ozzkoz]

I have a few questions regarding welding and how it is specified on drawings. I've checked a few texts but haven't quit gotten exactly what I'm looking for.

First off, fillet and butt welds. Do they always have some filler material which is added or are the pieces just melted together? How do you use the weld symbol to to specify what the filler material should be?

Second, if I want to weld two plates end to end with a V butt weld, do I design the two plates to have the chamfered edges or does specifying a V weld through the weld symbol imply that the welder modify the plates in order to add the V shape to the edges?

Lastly, if I have a sheet metal part which is to be slid into a "trough" of another part and want to weld the two together, is it a fillet weld and does it require filler or is it a seam weld I am looking for where I'd weld straight through the sheet and melt it to the bottom of the "trough".

I know these are really basic but all I've come up with is are descriptions of the weld symbols and how the different processes work (Laser, resistance, etc).

 

[berkshire]

ozzkoz
go to

https://ssl.lincolnelectric.com/foundation/

They have books there that will answer all of your questions.
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

 

[rmw]

This book is worth its weight in gold.

https://ssl.lincolnelectric.com/foundation/item.asp?prodnum=DW&PID=16

Berkshire - Thanks, I have a copy but didn't know where to get another one for colleagues.

rmw

 

[racookpe1978]

If you are the one specifying the welds on the drawings for a registered product or design - get help and some more training quickly. Get ALL of your designs and weld decisions reviewed in detail - and just "checked off" - by another engineer in your company to double-check your assumptions. At this stage of your training, you have no "designs" or calc's to base your weld symbols and the product design, only what can best be described as assumptions for what to do. Now, granted, your assumptions may not be wrong - but you can't tell me they are "right" either. And they most certainly won't be optimized for economy or ease of fabrication or length of service either.

Your questions are appropriate and represent the beginning of your education, but if they represent your level of experience, then you need more training before signing off drawing where lives and safety (mechanical, structural and product failures) are possible if your specified welds fail. I applaud your diligence in getting help, in recognizing you need training, but don't assume you have the detailed knowledge about welding to decide what to put in a weld symbol for any critical or important product. Yet.

It will come.

 

[ozzkoz]

We don't really do any welding other than welding disks onto pieces to create seals. Nothing structural and no one at my company can really help. We typically just write "weld around this edge". I'm trying to understand joints a little more.

 

[SnTMan]

ozzkoz, consider talking to your welders?

Regards,

Mike

 

[gadkinsj]

I find that my company has engineers that just use a note that says 'welded construction'. And these are on machines about the size of a 2 story ranch house. This wasn't much of a problem when we still had in house fabrication as at least the welders were well trained. But now we go to lowest bidder and sometimes get stuff fabricated in china, India, South America. I have been pushing the need to review drawings and get weld symbols updated but it hasn't been a priority.
Kudos to you for recognizing that a note just doesn't cut it, and trying to learn more. I plan on getting a couple welding certs just so that I can better learn what I'm really asking for.

 

[connectegr]

For my CWI test, I reviewed a book called Welding Inspection Technology. The book is available from AWS Education Services, and is a pretty comprehensive book. There examples of most structural welding processes, weld details, symbols, etc. And probably most important is the terminology.

There is a big gap between a "welded construction" note and selecting the most fabrication economical weld detail. Most engineers try to fall somewhere in the middle. It is most important that the final weld provide adequate strength. I frequently see insufficient weld information, which can result in grossly inadequate welds. And frequently after welding, the differences can only be determine by NDT.

http://www.FerrellEngineering.com

 

[vanci]

This sounds like a good opportunity for your employer to send you to school for formal education/ training. In doing so you would have added job security and opportunity for advancement. There are many 2yr degrees offered at colleges around the country. Also, join AWS and start going to the meetings. Its a good way to meet local people that can answer questions for you.

 

[bernoullies123]

While training would be fantastic I can tell you from experience very few companies in this world will pay... so with that said...

First off, fillet and butt welds. Do they always have some filler material which is added or are the pieces just melted together? How do you use the weld symbol to to specify what the filler material should be?

Response: Either or, depending on the process of welding, but the majority is with a filler material.

Second, if I want to weld two plates end to end with a V butt weld, do I design the two plates to have the chamfered edges or does specifying a V weld through the weld symbol imply that the welder modify the plates in order to add the V shape to the edges?

Response: Assuming your V-butt is the full thickness then you do not have to design anything as it is assumed that the strength of the weld is the same as the thickness of the material. If only partial groove then your weld needs to be designed. V symbol will require that the pieces be chamfered prior to welding. (Note that a simple V symbol is full thickness unless a partial thickness is specially defined next the the symbol).

Lastly, if I have a sheet metal part which is to be slid into a "trough" of another part and want to weld the two together, is it a fillet weld and does it require filler or is it a seam weld I am looking for where I'd weld straight through the sheet and melt it to the bottom of the "trough".

Response: A bit too vague. Sheet metal in my experience is very thin, so fillet would probably be out. Seam weld sounds like a better fit.

@berkshire and rmw: Thanks for the links, will have to order me one of those books.

 

[gtaw]

Go to the ASME website (ASME.org) and look for their short course PD359, Practical Welding Technology.

It is a good primer for someone that needs some basic information about welding and especially welding symbols.



Best regards - Al