Needle Scalers

Yah Hey Der,
Some recent comments from you guys about using needle scalers for paint removal have me curious. I've never used one before and would like to know about your experiences with and preferences for them.

A catalog search revealed choices in the number, length, diameter, and material of needles; also barrel or pistol grip shape, and stroke length.
It appears that the "general duty" scalers have a longer stroke (1-2.5") while the "industrial duty" scalers have a shorter stroke range of (1/4 -1").

My anticipated uses are for paint and rust removal from cast iron and also for slag removal from an occasional welding project.

Thanks,

John

The short throw units are superior in my opinion. I rebuild / restore a lot of old GM trucks and find that degunking, rust and paint and under coat removal from frames an cast parts is easily accomplished with a needlescaler. It does well on weld slag as well.

Be forewarned that is does beat the crap out fo the surface finish . . . not good for anything you want to be really pretty.

Needle scalers really work best on thick layers of paint on cast iron or heavy steel. Very noisy, but not as messy as media blasting. Not for sheet metal.

For cleaning up parts too big to fit into my blast cabinet, I use wire brushes on my large and small angle grinders then follow up in places I couldn't get to with the needle scaler -- it works real well in corners.

A needle scaler is one of my "indispensible" tools. Mainly for for peening and de-scaling welds. But also for other uses mentioned. It is a great tool for "faking" a casting out of a weldment. Get the part all welded up, grind to blend the corners and welds. Then hit it all over with the scaler and it puts the perfect smooth sand cast casting look on it. Not only that, but it is good for stress releif if done before machining.

Personally, I would not use a needle scaler indiscriminately on cast machine parts for removing paint. I have used it to straighten thin, large castings such as a 12" jointer fence, by bending the casting over some boards with clamps and peening the back with the scaler. Point being, these can move and pein the metal enough to distort a precision component. They surface compact the metal, which is generally "good". But that effect applied randomly can cause a powerful force both to relieve stresses, or to add them in ways that can cause warping.

smt

When stripping paint with a needle scaler, I hold about a 30-45 degree angle instead of straight on. This lessens the likelihood of bending a part. Even sandblasting can bend sheetmetal and thin sections unless great care is exersized. There used to be a beautiful 65 Mustang in my neighborhood with a fender that was waved from over-enthusiastic sandblasting.

I also like it when the needles get worn to an angle (when they are usually replaced). In this condition, they'll still strip paint fast as you can work, but they don't beat up the surface quite as fast. Backing down the pressure also helps. I had been running wide open, but put a combo reg/dryer/oiler inline the other day. I dropped from 130psi to 90 with no real noticable difference in performance, but the compressor sure likes it better.

I have also used that "simulated casting" technique. It really works nice.

HF has one for about $60, but Northern has the same I-R that I have at work for only twice that. You'll never wear out the Ingersoll.

I think I paid 28.00 for my needle scaler. I mainly used it for concrete build-up on my skid steer bucket, But I loved it for stripping the very thick very old paint from my bridgeport. It flew off as fast as I could pass the scaler across it. I was using very little pressure (hand)
too. I swept up the paint chips and disposed of them properly.
I will not use it on my Southbend 13" because the paint is not that thick. Oh yea, I can't stress enough the importance of eye and EAR protection. I'm sure my neighbor was wondering what the hell I was doing in that shop at 11.30 pm.

Isn't there a similar tool with a single needle or chisel tip? I vaguely remember that museum workers use something like this to clean up dinosaur bones. My vague memory comes up with the name "air scribe" or something like that.

Not really relevant, just curious...

Scott

The tips of my needles are rounded (I stick the scaler into a coffee can filled with small pebbles and sand) and wiggle it around while depressing the trigger.

Reducing regulator pressure, the scaler does a good job of peening and, as mentioned above, making a reasonable facsimile of a casting from a snall weldment.

Hi Guys,
Thanks for all the great feedback. It looks like I have to have one, too.

Thanks again,

John

They make great plannishing hammers too!

Forgot to mention... Don't put a quick-disconnect fitting directly on the back end of the scaler. I had one break and another totally ruined before I caught on to what was happening. The vibrations eat the male part of the connector up. Run a length of hose to absorb shock and put the connector on the end of that. You also need a dryer in the line. Yes, eye and ESPECIALLY ear protection are a must with this thing. Kind of like having a chain saw exhaust in your ear.....