Shop Floor Talk  

Go Back   Shop Floor Talk > Welding and Metalworking Forums > Fabrication

SFT Search:   
Reply
 
Thread Tools Display Modes
  #11  
Old 05-23-2019, 04:50 AM
MetalWolf's Avatar
MetalWolf MetalWolf is offline
Lubrication Consultant
 
Join Date: Jan 2011
Location: La Vernia,Tx.
Posts: 3,545
Default

Quote:
Originally Posted by Ironman View Post
I never preheat. I find the smoothness of cut is all about consistency of speed, distance from surface, and the correct sized tip for the job.

If you don't jerk and wallow and tilt the torch tip at right angles to the direction of cut it comes out nice. That is hard for some to do because age is stealing our skills.
Yep, yep, I know all about that and now as your, saying age is stealing our skills I guess that is where when it really doesn't matter and just cutting it is all that matters just getting it cut is a win sometimes

But as Walker said too "plasma cutters" is the way of life for a lot of us now. it as well takes away from the skill and art of cutting with O/A gas.

I have to cut a piece of steel I look over at the O/A torch and then the plasma and well I'll grab the plasma over the gas torch... it sort of getting left to the wayside but I still won't get rid of it... may not be the need as much as use to... but there will always be a need to have an O/A set handy cause you will find the need for it... that a plasma is just not a suitable tool to use.
Reply With Quote
  #12  
Old 05-23-2019, 06:52 AM
LKeithR's Avatar
LKeithR LKeithR is offline
Hey...wait...is there a prize?
 
Join Date: Aug 2011
Location: Langley, B.C.
Posts: 5,095
Default

Quote:
Originally Posted by MetalWolf View Post
...I have to cut a piece of steel I look over at the O/A torch and then the plasma and well I'll grab the plasma over the gas torch... it sort of getting left to the wayside but I still won't get rid of it... may not be the need as much as use to... but there will always be a need to have an O/A set handy cause you will find the need for it... that a plasma is just not a suitable tool to use...
Absolutely. We don't use our O/A torches nearly as much as we used to but there's no way we could run the shop without it...
__________________
Keith

Measure twice and cut once...or...wait, was that the other way around?
Reply With Quote
  #13  
Old 05-23-2019, 07:30 AM
camdigger's Avatar
camdigger camdigger is offline
Roving Reporter
 
Join Date: Aug 2008
Location: Central Oilberta
Posts: 3,668
Default

I don't preheat, but I have been known to raise a burr with a chisel to start a cut if one is handy. It shortens the time for it to heat up so the cut can be started.


Sadly, most times it would take more time to gather up a chisel and hammer than the time it takes to start the cut.
__________________
Design to 0.001", measure to 1/32", cut with an axe, grind to fit..
Reply With Quote
  #14  
Old 05-23-2019, 09:20 PM
milomilo's Avatar
milomilo milomilo is offline
Auction Addict
 
Join Date: May 2010
Location: Wheatland, Wyoming
Posts: 15,404
Default

I preheat to remove any surface moisture and to remove mill scale prior to layout.
__________________
Chris

Liberty has never come from Government. Liberty has always come from the subjects of it. The history of liberty is a history of limitations of governmental power, not the increase of it.
Woodrow Wilson
Reply With Quote
  #15  
Old 05-23-2019, 09:53 PM
Camaro Zach's Avatar
Camaro Zach Camaro Zach is offline
Senior Member
 
Join Date: Jan 2006
Location: Alvin Texas
Posts: 728
Default

Quote:
Originally Posted by camdigger View Post
I don't preheat, but I have been known to raise a burr with a chisel to start a cut if one is handy. It shortens the time for it to heat up so the cut can be started.


Sadly, most times it would take more time to gather up a chisel and hammer than the time it takes to start the cut.
I am going to have to try that, thanks!

I clean/swap tips almost every time I grab the torch to just to size the tip accordingly.

I hand cut some 2” plate recently with satisfactory results. No preheat other than burning the scale as others have mentioned. In the spot I couldn’t start on an edge I did drill a 1/4” through hole though.
__________________
Buggy
Reply With Quote
  #16  
Old 05-24-2019, 02:17 PM
Shade Tree Welder's Avatar
Shade Tree Welder Shade Tree Welder is offline
Grumpy Bastard
 
Join Date: Jun 2004
Location: Kankakee County, IL
Posts: 19,683
Default

Quote:
Originally Posted by Ironman View Post
I never preheat. I find the smoothness of cut is all about consistency of speed, distance from surface, and the correct sized tip for the job.

If you don't jerk and wallow and tilt the torch tip at right angles to the direction of cut it comes out nice. That is hard for some to do because age is stealing our skills.
Gerry and I have the same thoughts.


If you have to preheat you need a bigger tip. I have cut up to 4" plate,
no preheat needed, but earplugs helped.
__________________
Shade

"Prepare to defend yourselves."
-- Sergeant Major Basil L. Plumley, Ia Drang Valley
Reply With Quote
  #17  
Old 05-24-2019, 02:22 PM
Shade Tree Welder's Avatar
Shade Tree Welder Shade Tree Welder is offline
Grumpy Bastard
 
Join Date: Jun 2004
Location: Kankakee County, IL
Posts: 19,683
Default

Another boobtoob video on how not to do something. With all the preheat
his top edge is rounded over... My chief in the Navy would be chewing his
ass...
__________________
Shade

"Prepare to defend yourselves."
-- Sergeant Major Basil L. Plumley, Ia Drang Valley
Reply With Quote
  #18  
Old 05-24-2019, 08:39 PM
digger doug's Avatar
digger doug digger doug is offline
Not to be used as a Flotation Device
 
Join Date: Jan 2008
Location: NW Pa
Posts: 11,862
Default

Quote:
Originally Posted by Shade Tree Welder View Post
Another boobtoob video on how not to do something. With all the preheat
his top edge is rounded over... My chief in the Navy would be chewing his
ass...
Yup, that is a problem I have with my simple little CNC table cutting 3/4" or thicker.

I have to run the preheat up high to get started, and don't have the fancy
5 regulator system like the fancy machines to drop the preheat after pierce.

So I doo get more round over than I would like.
Reply With Quote
  #19  
Old 05-25-2019, 10:02 AM
LKeithR's Avatar
LKeithR LKeithR is offline
Hey...wait...is there a prize?
 
Join Date: Aug 2011
Location: Langley, B.C.
Posts: 5,095
Default

Quote:
Originally Posted by Camaro Zach View Post
...I clean/swap tips almost every time I grab the torch to just to size the tip accordingly...
Having a clean, properly sized tip makes a huge difference in how well an O/A torch works. Back in '69 when I first started hackin' and tackin' metal most small shops didn't have the options for cutting steel that are available today. No plasma, laser or waterjet cutters; abrasive saws were pretty much confined to larger shops, zip discs didn't exist and bandsaws were few and far between. Other than an O/A torch a cheap, import power hacksaw was probably the first metal cutting tool that most of us had.

We had to learn how to use a torch properly; selecting the right size tip, keeping it clean and knowing how to start a cut with minimum preheat were basic skills. We had to because there often were no alternatives. Today, while we still keep a torch in the shop, we don't use it very often--more frequently for heating something rather than cutting it. And on the odd occasion where something needs to be cut with a torch I'm often guilty of grabbing it and just using whatever tip is already there. Unless the tip is grossly over or under-sized for the material being cut it doesn't get changed.

Quote:
Originally Posted by Shade Tree Welder View Post
...If you have to preheat you need a bigger tip. I have cut up to 4" plate, no preheat needed, but earplugs helped...
Yup, set up properly an O/A setup is still the most practical way to cut thicker materials...

Quote:
Originally Posted by digger doug View Post
...I have to run the preheat up high to get started, and don't have the fancy 5 regulator system like the fancy machines to drop the preheat after pierce.

So I doo get more round over than I would like...
But it's the machines fault, right?
__________________
Keith

Measure twice and cut once...or...wait, was that the other way around?
Reply With Quote
  #20  
Old 05-25-2019, 02:27 PM
MetalWolf's Avatar
MetalWolf MetalWolf is offline
Lubrication Consultant
 
Join Date: Jan 2011
Location: La Vernia,Tx.
Posts: 3,545
Default

Quote:
Originally Posted by LKeithR View Post
Having a clean, properly sized tip makes a huge difference in how well an O/A torch works. Back in '69 when I first started hackin' and tackin' metal most small shops didn't have the options for cutting steel that are available today. No plasma, laser or waterjet cutters; abrasive saws were pretty much confined to larger shops, zip discs didn't exist and bandsaws were few and far between. Other than an O/A torch a cheap, import power hacksaw was probably the first metal cutting tool that most of us had.

We had to learn how to use a torch properly; selecting the right size tip, keeping it clean and knowing how to start a cut with minimum preheat were basic skills. We had to because there often were no alternatives. Today, while we still keep a torch in the shop, we don't use it very often--more frequently for heating something rather than cutting it. And on the odd occasion where something needs to be cut with a torch I'm often guilty of grabbing it and just using whatever tip is already there. Unless the tip is grossly over or under-sized for the material being cut it doesn't get changed.



Yup, set up properly an O/A setup is still the most practical way to cut thicker materials...



But it's the machines fault, right?
The only reason I preheat thick metal is I use a small Victor Jr. torch..NO not quite the proper torch to use for cutting 1" thick plate But I can cut it with the torch I have. another reason is I don't normally have a need to cut anything thicker than 3/4" and that is only once in a while mostly it's 1/4" to 1/2"
and the V, Jr. will do it quite nicely...

So I do use a larger tip I do keep my tip clean but if the regular need for cutting thick materials above 1/2" is not there then no need to have a larger torch and preheating or drilling a through hole serves the intended purpose.

But most of the cutting needs for thicket metal/materials I usually need can be done with the porta band or on the band saw or my gas powered portable chop saw, in any event, I will get it cut however I need...

So I don't see where all this went form a DIY tips and tricks video to the limp noodle contest... when preheating or drilling a through hole in thicker metal does work when your torch is inadequate in its ability you can still get the job done.
Reply With Quote
Reply

Thread Tools
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

Web Search:

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


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.