Slag buster

Welding Techniques, Theory, Machines and Questions.

Moderators: Harold_V, Scott

Glenn Brooks
Posts: 890
Joined: Mon Nov 10, 2014 1:39 pm
Location: Woodinville, Washington

Slag buster

Postby Glenn Brooks » Thu Apr 20, 2017 9:45 am

Just discovered a new way to remove slag from small, tight, inside corner welds. Got tired of repeatedly hand scraping inside corner welds to get rid of slag, splatter, and etching residue from priming with Ospho. So yesterday experimented with using an air powered needle gun to clean up this bunch of inside corner welds i have been working on. Works great! So far...

First I bought a small high speed air grinder. It works pretty well, but is hard to control due to hi torque, and doesn't work well when removing splatter. Angle grinders don't reach inside the 2" or 3" radius of the wheel. So always have reverted back to hand chipping and scraping all the slag and welding by product from each corner weld.

ON a whim, tried a Cheapo Harbor Freight needle gun and was very happy with the result. Seems to work better with the outer rim of needles removed from the gun- working the deep pockets and corners with the remaining smaller diameter bunch of needles in the center of the gun. Just like knocking rust off the surface of junkyard steel.

I think this will be my go to tool for future welding projects.

Glenn
Moderator - Grand Scale Forum

Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....

User avatar
warmstrong1955
Posts: 2752
Joined: Thu Mar 18, 2010 2:05 pm
Location: Northern Nevada

Re: Slag buster

Postby warmstrong1955 » Thu Apr 20, 2017 10:22 am

I have two needle scalers.
A good one, a Sioux, and a Horror Freight cheapie. I bought the HF one for home, since my Sioux was always at a job somewhere.

For the money, my HF does very well. Not a bad choice. I think it was copied from the Sioux.
My HF looks like this one....mine is 20 years old, so may not be the same model.
http://www.harborfreight.com/air-needle ... -1108.html

Not the power as my USA one, but plenty good enough. Mine had a loose fit between the body & the front housing, and would turn and adjust itself or come loose all the time. I put a worm gear clamp to squeeze the front housing tighter, where it's slotted. Thought it might shake loose, but has never been a problem. It's been on a lot of jobs as well, so it's not like I haven't used it. I did replace the needles a few years ago. Got some from a local welding supply place in Montana.

Bill
Today's solutions are tomorrow's problems.

Glenn Brooks
Posts: 890
Joined: Mon Nov 10, 2014 1:39 pm
Location: Woodinville, Washington

Re: Slag buster

Postby Glenn Brooks » Thu Apr 20, 2017 3:32 pm

Bill, yep, that's the model I am now using. It's borrowed, so I need to go buy one. Can't believe more welding sites don't recommend use of these things!

Glenn
Moderator - Grand Scale Forum

Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....

User avatar
warmstrong1955
Posts: 2752
Joined: Thu Mar 18, 2010 2:05 pm
Location: Northern Nevada

Re: Slag buster

Postby warmstrong1955 » Fri Apr 21, 2017 11:57 am

Don't know....I thought they were a 'gimmee'. Big time saver if your welding with stick.
I bought my Sioux at least 40 years ago. Used at a swap-meet in Tucson. Horror Freight one....in the mid 90's.
If you get the HF, hope it holds up as well as mine! I wore out a set of needles with it. Pretty good for something that cost about 25 bucks at the time!

Bill
Today's solutions are tomorrow's problems.

dbstoo
Posts: 31
Joined: Sun Oct 05, 2014 11:45 pm

Re: Slag buster

Postby dbstoo » Fri Apr 21, 2017 2:23 pm

I used one to take the paint off of my MIL's (mother in law) favorite sprinkler prior to welding the stamped steel base back up so it could be staked to the pot-metal main part again. The paint was covering rust, but was secure enough that wire brushes were not knocking it loose.

The small HF needle de-scaler pounded the rust under the paint to dust and cracked the paint so that a wire wheel could get a grip.

Dan

spro
Posts: 6477
Joined: Mon Feb 20, 2006 11:04 pm
Location: mid atlantic

Re: Slag buster

Postby spro » Sat Apr 22, 2017 6:07 pm

Needle scalers are the way to go. We've mentioned them for years. There are different size "nozzles" and diameter of the needles to where they fit on an impact gun. These units require a lot of air gun oil for they get right hot and can wear out. The individual "needles" become dull quickly and need resharpening but it is cool. They can be ground (usually flat) and quenched to be good as new. Man when we were cleaning out the insides of of boilers or chillers, stuff maybe ankle deep in water. pneumatic was the way to go. The Real deal is superb and the HF not too bad either. When the needles all have that edge, they chip away like nothing else.

User avatar
warmstrong1955
Posts: 2752
Joined: Thu Mar 18, 2010 2:05 pm
Location: Northern Nevada

Re: Slag buster

Postby warmstrong1955 » Sat Apr 22, 2017 6:19 pm

Yes indeed!
Another thing we used them for, was on shotcrete machines to chip off all the build up of concrete. Big stuff you can use a air chisel, but needle scalers get into all those nooks & crannies, which is really nice when you are looking for bolt heads & nuts to take a pump, sprayer or mixer apart!

:)
Bill
Today's solutions are tomorrow's problems.

b4autodark
Posts: 16
Joined: Fri Dec 16, 2016 9:06 am

Re: Slag buster

Postby b4autodark » Sat Apr 22, 2017 8:29 pm

Used a needle gun for years for slag removal and peening welds on the job, now since two shoulder surgeries I even use one to clean the bottom of my lawn mower deck.

User avatar
warmstrong1955
Posts: 2752
Joined: Thu Mar 18, 2010 2:05 pm
Location: Northern Nevada

Re: Slag buster

Postby warmstrong1955 » Sat Apr 22, 2017 8:36 pm

b4autodark wrote:Used a needle gun for years for slag removal and peening welds on the job, now since two shoulder surgeries I even use one to clean the bottom of my lawn mower deck.


Hey....spring has sprang and I'm gettin' ready.....I just used mine to my garden tractor mower deck today!

And, like you say, works great for peening welds, which is generally a must with cast iron, and welding dissimilar metals for stress relief!

:)
Today's solutions are tomorrow's problems.


Return to “Welding”

Who is online

Users browsing this forum: No registered users and 2 guests