Go Back OFN Forums > Fabrication > Fab School Forum

Fab School Forum www.thefabschool.com


Fab School Forum www.thefabschool.com

Reply
 
Thread Tools
  #1  
Old 06-30-2013, 12:36 PM
Defender Chassis's Avatar
Defender Chassis Defender Chassis is offline
Master Fabricator
 
Join Date: Nov 2006
Location: Mid-Ohio Valley
Posts: 412
Stacking tacks....

http://www.youtube.com/watch?v=8QU9OAerWYI

Fab School,

Please read the comments below the video and respond. The event I am referencing can be seen at 1:22 & also a short section at 2:25.

Regards,
Scott Matheny

Last edited by Defender Chassis; 06-30-2013 at 12:44 PM.
Reply With Quote
  #2  
Old 06-30-2013, 08:33 PM
wyoming9's Avatar
wyoming9 wyoming9 is offline
Master Fabricator
 
Join Date: Aug 2008
Location: New Tripoli Pa. out in the woods
Posts: 2,202
Red face

One way to solve this question

two test coupons same joint every thing the same but welding style

break it in a tensile test.

If that does not settle it do two more prepare correctly and do a bend test.

Let the best weld win!!
__________________
Some days it takes longer to pick which welder

then to do the welding
Reply With Quote
  #3  
Old 06-30-2013, 11:11 PM
Ian from Xtreme's Avatar
Ian from Xtreme Ian from Xtreme is offline
Moderator
 
Join Date: Feb 2007
Posts: 225
I performed a "non" scientific test on "stitch" welding similar to that, pieces of tubing welded in an 'H'. One joint bead welded, and the other one stitched, put it in the press and kept adding pressure until one failed.....the stitch always failed.

I used to have alot of 'discusisons' about this type of welding, I never felt that it was strong just because of the theory behind it. When welding light sheet metal the process of stitch welding or tacking is used to limit heat input into the metal to prevent warpage. Limiting heat input into a tube joint just never seemed like a good idea.
Reply With Quote
  #4  
Old 07-01-2013, 12:05 AM
dean's Avatar
dean dean is offline
Fabricator
 
Join Date: Feb 2012
Posts: 77
i've read this argument on so many forums and threads it's stupid!
is one piece of metal (continuous weld) stronger than tack,tack,tack,etc(many pieces welded together)
honestly,think about it and make up your own mind.
Reply With Quote
  #5  
Old 07-01-2013, 02:42 AM
JaysinSpaceman's Avatar
JaysinSpaceman JaysinSpaceman is offline
Master Fabricator
 
Join Date: Feb 2008
Location: Skull County, Ca
Posts: 1,637
All I know is that there is absolutely nowhere in any welding code that says that stack-o-tacks is even OK. And there are many places in code that require grinding out starts and stops before the next weld is made.

Limiting heat input on sheet metal (under 14g) is understandable as excessive heat can cause burn through and warpage, and even the tack-tack method can make a full penetration weld on say 16g sheet. But even here you have a cold lap at every tack and this is the weak point on just about any weld, this is why they use runoff and start plates on things like Sub-arc and many heavy weldments.

But then, some guy in his back shed will tell me that he knows it's just as strong because his brother's kid's uncle-dad's chicken coop ain't never felled down and that's how they welded it up. Screw the code or scientific testing methods or common sense.

This is a stupid argument and it, unfortunately, will not even be settled when the American Welding Society actually publishes a scientific test because stupid people will continue to believe stupid things regardless of proof.

Jaysin
Reply With Quote
  #6  
Old 07-01-2013, 12:10 PM
Defender Chassis's Avatar
Defender Chassis Defender Chassis is offline
Master Fabricator
 
Join Date: Nov 2006
Location: Mid-Ohio Valley
Posts: 412
In the interest of adding clarity, I did not start this thread to debate "stacking tacks" vs. a continuous weld. I started it because I seem to remember some time back that there was a discussion, on this board I think, in which the Fab School was criticized for teaching what was then called the "ticky tacky" method of welding. The owner or another rep from the school vehemently denied the accusation at the time. This is all of course if my memory serves me correctly. It may have not even been this school. It may have been the one that lets you build your own desert tube buggy. Anyhow, I found it odd that not only the Fab School but also Miller would put out a video that featured this method.
Reply With Quote
  #7  
Old 07-01-2013, 01:00 PM
Defender Chassis's Avatar
Defender Chassis Defender Chassis is offline
Master Fabricator
 
Join Date: Nov 2006
Location: Mid-Ohio Valley
Posts: 412
I posted the video on the Fab Schools Facebook page and asked the following:

Hi Scott. We do not teach structural steel welding. I hope this answers your question. Thank you and have a great day!

I responded with the following:

When I said "structural welds" I did not mean structural steel such as I-beams and such. By "structural welds" I mean a weld in which strength is a concern. In the video the operator is welding what appears to be a tube on a chassis. This would normally be a weld in which strength would be a concern as opposed to say a sheet metal body panel on a car. The question remains unanswered.

Do you think it is there position that they do not teach welding where strength is a concern or do they just not understand the question?

https://www.facebook.com/#!/TheFabSc...ocation=stream

https://www.facebook.com/#!/TheFabSc...=share_comment
Reply With Quote
  #8  
Old 07-01-2013, 01:59 PM
FABSCHOOLDION's Avatar
FABSCHOOLDION FABSCHOOLDION is offline
Junior Fabricator
 
Join Date: Apr 2013
Posts: 7
Hi Scott.

Hi Scott.

We try and teach all methods of welding. Whether it is continuous or pulse, our priority is giving our students hands on experience on the best methods to do either. Some employers would like to see if students are versed in all aspects of welding and in the student’s best interest as well as the potential employers.

“Stacking tacks” is an unfamiliar term so I am assuming you are speaking about pulsing. When we use the pulse method, it has to be done with a machine that can carry the amperage. The machine is turned up during this process which helps us to carry the heat from our last pulse to the next. Many shops use this technique in there day to day builds. Pulse can only be done with light material. It is not meant for structural steel and only for materials .120 or smaller material.

Thank you and I hope this clarifies your concerns. If you have any additional questions feel free to contact us at our office anytime. 951.782.0567

Have a wonderful day!
Reply With Quote
  #9  
Old 07-01-2013, 02:04 PM
Defender Chassis's Avatar
Defender Chassis Defender Chassis is offline
Master Fabricator
 
Join Date: Nov 2006
Location: Mid-Ohio Valley
Posts: 412
Did you actually watch the video?
Reply With Quote
  #10  
Old 07-01-2013, 02:24 PM
mfs's Avatar
mfs mfs is offline
Fabricator
 
Join Date: Jul 2009
Location: san diego, ca.
Posts: 73
Lol this is funny The Fab school Harlem shake
http://youtu.be/zzw0YgJzXOg
Reply With Quote
  #11  
Old 07-01-2013, 07:55 PM
350 Vortec's Avatar
350 Vortec 350 Vortec is offline
Master Fabricator
 
Join Date: Jun 2011
Location: Ireland
Posts: 489
Mig weld like that around here and you'll get a swift boot out the door,sure it looks nice but so would a stack of tacks from a silicone gun...
Reply With Quote
  #12  
Old 07-02-2013, 03:13 PM
wyoming9's Avatar
wyoming9 wyoming9 is offline
Master Fabricator
 
Join Date: Aug 2008
Location: New Tripoli Pa. out in the woods
Posts: 2,202
Red face

Wow by there own admission the Fab school only teaches welding suitable for patching body panels.

Nothing what ever to do with any structural welding what ever.

No frame work No cage work no suspension work.

No load bearing type of welding at all .

No doubt a insurance risk they can`t afford.

Good to know!!
__________________
Some days it takes longer to pick which welder

then to do the welding
Reply With Quote
  #13  
Old 07-05-2013, 11:50 PM
David D's Avatar
David D David D is offline
Fabricator
 
Join Date: May 2007
Posts: 51
Quote:
Originally Posted by FABSCHOOLDION View Post
“Stacking tacks” is an unfamiliar term so I am assuming you are speaking about pulsing. When we use the pulse method, it has to be done with a machine that can carry the amperage. The machine is turned up during this process which helps us to carry the heat from our last pulse to the next. Many shops use this technique in there day to day builds. Pulse can only be done with light material. It is not meant for structural steel and only for materials .120 or smaller material.
The welding you are describing is not pulse welding. Pulse welding requires a specialized machine, and the arc is continuous. It bounces back and forth between a normal voltage, and a background voltage.
Reply With Quote
  #14  
Old 12-13-2013, 02:03 PM
Bent's Avatar
Bent Bent is offline
Junior Fabricator
 
Join Date: Dec 2012
Posts: 17
Even though this thread is old, I figured I would add my 2 bits...

Being a professional welder for over 30 years, my opinion is:
The strength of a mig weld is not determined by the technique used. It is determined by the set up selected prior to welding.

Through the years, What I have observed about mig welding is...most "hobby" mig welders can weld like a pro with one machine and not worth a dam on another. This is because they were never taught how to set up a machine to weld on different materials.

Carbon Steel, Aluminum, Stainless Steel all require differing gases, consumables and machine adjustments.

Sticking to Carbon Steel, specifically, the tubing being welded in the first post's youtube link.
The person performing the weld seems to be doing it properly! His steps are to the leading edge of the previous one, which will give good penetration. The machine seems to have the voltage and wire feed set properly for good penetration as well and he has lots of re-inforcement. From the video, I think the machine is set to spray transfer, which gives good penetration with little to no spatter.
When done properly, a mig weld is actually stronger than a stick weld! (<---I have proven this time and again)

Personally, if I was to build a roll cage, I would stick weld it in position because of the ease and speed. Mig welding would be my 2nd choice for its ease and little to no clean up. Even though Tig welding has the nicest finish, it wouldn't be an option for me because it's so time consuming...and out here, time is money.

Last edited by Bent; 12-13-2013 at 02:05 PM.
Reply With Quote
  #15  
Old 12-15-2013, 07:07 PM
projectdiy's Avatar
projectdiy projectdiy is offline
Junior Fabricator
 
Join Date: Dec 2013
Location: Shreveport , LA
Posts: 2
Hi Bent, I am new to the forum and am sure I will gain much from the knowledge of the individuals like yourself.

The project I am going to start shortly is a mini jeep on a mower frame. The body will be made of mild steel sheet and I plan to use 16 gauge reinforced with square tubing. I am checking to see if you think 16 g is thick enough with a mig welder.
Reply With Quote
  #16  
Old 12-15-2013, 08:46 PM
projectdiy's Avatar
projectdiy projectdiy is offline
Junior Fabricator
 
Join Date: Dec 2013
Location: Shreveport , LA
Posts: 2
Stacking Tack

Quote:
Originally Posted by projectdiy View Post
Hi Bent, I am new to the forum and am sure I will gain much from the knowledge of the individuals like yourself.

The project I am going to start shortly is a mini jeep on a mower frame. The body will be made of mild steel sheet and I plan to use 16 gauge reinforced with square tubing. I am checking to see if you think 16 g is thick enough with a mig welder.
I hope that this project will come together well.
Reply With Quote
  #17  
Old 12-15-2013, 08:52 PM
Bent's Avatar
Bent Bent is offline
Junior Fabricator
 
Join Date: Dec 2012
Posts: 17
Kinda hijacking this thread but...
16 Gauge is about a 1/16th of an inch thick, which would be just fine for body skin. Make sure your tubing is of an adequate grade for the frame. Up here, most structural steel is garbage! No strength whatsoever.

As for welding 16 gauge...A mig would be a good choice for sure. I would use an .023 wire and go with Argoshield universal for the shielding gas.

Warpage may be an issue, so make sure you tack your work every few inches and maybe use a backing plate if needed.

If you can weld the body panels in the flat...I would set the mig up for globular transfer (not for structural though), it will give you a good weld with little warpage but not much penetration, which would be ok for the body panels.
Reply With Quote
  #18  
Old 02-02-2014, 04:54 PM
racer-john's Avatar
racer-john racer-john is offline
Fabricator
 
Join Date: Jan 2009
Location: Newmarket, ON Canada
Posts: 32
"Bent"

Where is "Up here" (your location?)
Reply With Quote
  #19  
Old 02-04-2014, 07:21 PM
dean's Avatar
dean dean is offline
Fabricator
 
Join Date: Feb 2012
Posts: 77
Quote:
Originally Posted by racer-john View Post
Where is "Up here" (your location?)
i'm really hoping "up here" isn't canada!
if that's the case i have some recalling to do!
oh wait,my lifetime warranty means the lifetime of the product,whew had me sweating for a moment
Reply With Quote
  #20  
Old 02-05-2014, 05:26 PM
rdn2blazer's Avatar
rdn2blazer rdn2blazer is offline
Master Fabricator
 
Join Date: Nov 2007
Posts: 773
A tack is a weld tack to hold a fab job together with so you can then fully weld it period. ANY form of welding in this manor other then tacking to hold or thin sheetmetal work is just stupid.
Reply With Quote
Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

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 -4. The time now is 06:32 AM.

Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Template-Modifications by TMS
Copyright ©2012, Offroad Fabrication Network