All MetalShaping

Go Back   All MetalShaping > General Metal Shaping Discussion > Welding Sheet Metal
  Today's Posts Posts for Last 7 Days Posts for Last 14 Days  

Reply
 
Thread Tools Search this Thread Display Modes
  #11  
Old 02-04-2021, 09:50 AM
Bibbt Bibbt is offline
Member
 
Join Date: Jan 2021
Location: San Antonio,Texas
Posts: 20
Default

Steve,
Thanks for the suggestion. I had my tips on and off yesterday to redress them several times and didn't find any corrosion. Mine actually had some sort of compound on the threads that I assume helps prevent corrosion. I'm gonna do more testing today. Bob had some good suggestions I am going to try but I am thinking my problem might be too powerful a machine for what I am welding. Combined thickness of .040 is pretty thin. I thought this was gonna be easy...

Thanks,
Bibb in San Antonio
__________________
Bibb
Reply With Quote
  #12  
Old 02-04-2021, 12:19 PM
mastuart mastuart is offline
Member
 
Join Date: Oct 2016
Location: Mendota Il
Posts: 66
Default

I have 2 of the miller spot welders. 1 is a 220 unit on a stand like you have. It has 18 inch long tongs. It is a mean SOB. The other is a 110 unit. Not sure of the type stainless headlight retainer rings are but you can spot weld them with ease with the 110 unit. They are thin. You can also control the weld time by how long you clamp. The clamp turn the switch off and on regardless of the switch timer.
__________________
Mark
Reply With Quote
  #13  
Old 02-04-2021, 01:39 PM
Bibbt Bibbt is offline
Member
 
Join Date: Jan 2021
Location: San Antonio,Texas
Posts: 20
Default

Mark,
Thanks for the reply. So what do you estimate the thickness to be of the parts you have successfully welded with the 110 unit?

I'm attempting to spot weld two 1/2" type 304 stainless strips together with a combined thickness of .040" It's totally unrelated to automotive application. It's actually part of a 9 volt battery clip that I make for a vintage camera.

Heck , I hate to buy chinese knockoff tools but maybe I'll head over to Harbor Freight and get one of their 110 spot welders and give it a try. It's a whopping $150 I think.

Bibb in San Antonio
__________________
Bibb
Reply With Quote
  #14  
Old 02-04-2021, 07:01 PM
Bibbt Bibbt is offline
Member
 
Join Date: Jan 2021
Location: San Antonio,Texas
Posts: 20
Default New tips and test weld pics

So today I bought and installed a large flat tip on the bottom tong of my Miller spot welder. I ran some tests and the flat tip made a big difference. I have some photos of the front and back side for the experts to look at and hopefully give me some feedback. They still aren't as good as I would like but they are much better than my first attempt. I have my timer turned down to roughly 1/4 second which is a short as I could make it and get any consistency. My gut tells me my welder has too much current for what I am doing. In the photos, the 6 welds at the far right side of the material are my final welds and the best I could muster. I had to peel the metal off the top tip after almost every single weld. I'm thinking it shouldn't be that way. Please take a look and tell me what you think.
Thanks,
Bibb in San Antonio

IMG_2348.jpg

IMG_2349.jpg

IMG_2347.jpg
__________________
Bibb

Last edited by Steve Hamilton; 02-04-2021 at 07:42 PM. Reason: spelling error
Reply With Quote
  #15  
Old 02-04-2021, 08:32 PM
tom walker tom walker is offline
Member
 
Join Date: Dec 2010
Location: st.louis,mo.
Posts: 92
Default

Bibb, i have a couple Miller 120volt spot welders,if you want to you could send a couple of strips of material and i could give it a go. Before you go out and buy another welder, not knowing if it's going to work or not.
Tom
Reply With Quote
  #16  
Old 02-05-2021, 11:09 AM
bobadame bobadame is offline
MetalShaper of the Month Feb 2015
 
Join Date: May 2009
Location: Fort Collins, Colorado
Posts: 1,160
Default

To weld strips of equal thickness you should be using tips with the same shape top and bottom. This will concentrate the weld equally in the center of the strips. I think your radius is much too small. It's concentrating the squeeze force and heat in too small area. Take a piece of wood about 1/2 by 2" about 8" long and cover the flat sides with sand paper. Use it to re-shape the tips to a larger radius. When you begin to see good welds do just one weld per blank so that you can twist the pieces to test their quality. Read the section in the pdf that covers tip shape and size. Good luck.
__________________
Bob

Don't believe everything you think.
Reply With Quote
  #17  
Old 02-05-2021, 05:10 PM
Bibbt Bibbt is offline
Member
 
Join Date: Jan 2021
Location: San Antonio,Texas
Posts: 20
Default

Tom, that is a very generous offer. I might just take you up on it. I'm gonna try the advice Bob gave about making the tip contact area larger. If I still can't get what I'm looking for, I will send you some strips of material.

Thanks,
Bibb in San Antonio
__________________
Bibb
Reply With Quote
  #18  
Old 02-05-2021, 05:17 PM
Bibbt Bibbt is offline
Member
 
Join Date: Jan 2021
Location: San Antonio,Texas
Posts: 20
Default

Bob,
I will go back to a set of standard tips and sand them to make the contact area larger per your advice and see what happens. I sure would like to be able to accomplish my goal without buying another piece of equipment. I will post new photos after I modify the tips.

Thanks,
Bibb in San Antonio
__________________
Bibb
Reply With Quote
  #19  
Old 02-05-2021, 06:44 PM
tom walker tom walker is offline
Member
 
Join Date: Dec 2010
Location: st.louis,mo.
Posts: 92
Default

Bibb, i'm happy to help you out.
Tom
Reply With Quote
  #20  
Old 02-06-2021, 12:00 PM
Bibbt Bibbt is offline
Member
 
Join Date: Jan 2021
Location: San Antonio,Texas
Posts: 20
Default

Quote:
Originally Posted by bobadame View Post
To weld strips of equal thickness you should be using tips with the same shape top and bottom. This will concentrate the weld equally in the center of the strips. I think your radius is much too small. It's concentrating the squeeze force and heat in too small area. Take a piece of wood about 1/2 by 2" about 8" long and cover the flat sides with sand paper. Use it to re-shape the tips to a larger radius. When you begin to see good welds do just one weld per blank so that you can twist the pieces to test their quality. Read the section in the pdf that covers tip shape and size. Good luck.
Bob,
You were right on the money about my tips having too small a contact area. I went back to my standard pointed tips which had an estimated contact surface of about 5/32" and I ground them down to where they now have an approximate contact area of 3/8". It made all the difference in the world! Weld time is about 1/4 second. I have attached 2 photos of my test strip showing front and back. Per your instructions I did a test to see if I could tear the weld apart and I couldn't. I think with a little more fine tuning I can make them even better. In the end, this will all be worth it because being able to spot weld this part together instead of using a hollow eyelet will be fewer steps and less labor and is also stronger.

I will have to say that setting this up is more tedious than I expected. Getting a really nice, symmetrical weld nugget or "spot" isn't easy on this thin material. I think I'm used to seeing spot welds on high production items that are done with sophisticated/automated spot welding equipment. In the photos, there are 3 welds near the left edge that were my final welds. The one on the far right edge was my first one that I tried to tear apart. Please take a look at my latest attempt and tell me what you think.

Thanks,
Bibb in San Antonio

,IMG_2361.jpg

IMG_2362.jpg
__________________
Bibb

Last edited by Steve Hamilton; 02-06-2021 at 01:56 PM.
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -5. The time now is 03:26 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.