Is a DA sander the same thing as a random orbital sander? Does it matter if it's air driven or electric when doing body work? What are the advantages of a DA sander over another type of a sander when doing body and paint prep work? Thanks Steve
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Is a DA sander the same thing as a random orbital sander? Does it matter if it's air driven or electric when doing body work? What are the advantages of a DA sander over another type of a sander when doing body and paint prep work? Thanks Steve
DA or "Dual Action" is a predictable up-down and back-forth motion. Random action orbital is just as the name implies, a series of random movements in a circular pattern.
Electric is good. Most come with Velcro type pads in grits from 60 - 220. DeWalt, Ryobi, Makida on the less expensive end. Porter Cable and Milwaukee on the more expensive side.
For really super fine finish, Dynabrade or Hutchins (air driven) but they are expensive. Dynabrade 6" is $325+/-. Hutchins 6" will run $225. These are really good units but require a good flow of air (10CFM @ 90psi)
As its name implies, a DA sander or dual action can be used as a random orbital or a circular sander just by locking the pad with the locking device built into the shaft.
To answer your question about the advantages Steve, what it does is spread the sanding motion over a large area, unlike a disc sander that just spins and concentrates the grinding on a small area. DA's are great for final body work where you want to level out a large panel (like a hood). You simply start it and move it over the surface and it sands a little bit off without digging into any one spot. The "dual action" name comes from the fact that they 1) spin in a circle like a regular grinder and 2) travel in and orbital pattern to spread the sanding over a larger area.
We even have a couple of HF ones that aren't too bad, and for the average hobbyist they are fine.
Don
Thanks Guys. Don that discription makes the most sense to me. There are some hard to level spots on the cab and front fenders. After reading the new addition of Street Rodder, he is presenting a series of articles of how to go about painting your own car for reasonable amounts of cash. I figureI'll gieve it a try if I can get the body smooth enough to hide most of the dents that are currently driving me nuts! They are very subtle and usually only apparent after I shoot some primer over then. This info is for the spring when it's a little warmer out there. When I read the article in Street Rodder he says it's worth every penny to buy a DA sander( and like Don said) HF has them for 15-20 bucks so it may be worth it. My biggest worry is finding a space to paint, but in his article he says a garage is fine or even a driveway. I thought it might work to buy a temperary shelter(poles with plastic roof and sides) and spray in the driveway, to keep the garage from getting to messed up. Not sure how bad over spray is. So far the two part primer has made no mess!:D
I have an air and an electric da> the air DA is an air hog. I use my porter cable DA a bunch. It does a better job than my bluepoint air DA..
I have found that they all are great for making waves, especially if you tilt them at all. If I'm working on anything I really care about I put away the power tools after the metalwork is done and use a block from there.. It works well as long as you are mindful of cure times on fillers and glazes they cut very easily..
one thing about a da is you need a good pad like 3m i use 6 inch i like the palm type da s .and guys run them to fast burn paper up and shake the $hit out of what your tring to make flat you can get things very flat if you know what your doing with one but like any thing else can add to choppy work so there comes a time were you may want to use blocks or boards . when i did body and paint for a livining i used one all the time and used it up to paint prep and block wet sanded and to pad wet sand. before color and just went over with a block wet320to 400 to get any 66 out some guys call them 6or8s marks that is what the da makes as it sands if you used a guid coat you can get things flat with a da first things is hold it flat. watch your speed and slow the thing down keeps paper from pluging up and burning of the grit of the paper .use fresh paper and if you drop it you can bend the pad so you will need a new pad if you do not want to make more work:3dSMILE:
I like the DAs with the lock on them, which converts it to a light grinder. comes in handy occasionally, like when you find some unexpted ( light ) rust.
Electric would be useful if you are working in a cold shop. I have had air tools lock up when working in cold. The moisture in the air line will condense and freeze up the tool. Very annoying.
Thanks guys, what kind of block sanders do you recommend? I just have a little rectangular 3m household style, which doesn't work to well on long slightly curved areas.
we use to make some a good thick wooden paint stick re work a bit works good if curved and you can use rubber pads but you need to work it flat first you can do this by working by sanding a curved panel at a angle like a X with a long board and then work up to a paint stick to a med pad to a soft pad
I like the Dura-Bloc sanders. They sell a reasonably priced package of different sizes and configurations, and they also sell them individually. There are some better and much more expensive, too. Guess it depends on how much you're going to use them and how much you want to spend....
On the DA's, the air one's are made with different stroke lengths, too. I have a very short stroke Dynabrade DA that is my pride and joy!!! At low speeds and the correct pressure it does a fantastic job and requires less time with the hand blocks... When you get old and crippled up in the back, neck, arms, and hands it makes a big difference how much time you have to spend hand blocking!!!!
Thanks Dave. I picked up a set of Dura Blocks for 34 bucks on Ebay, and am looking at used DA sanders vs. new. The Dynabrade's must be good, they sell for a premium on ebay. Has anyone used Ingersol Rand. They make a six inch which is billed to be quiet. Since my 3" cutting tool makes me deaf for a few hours every time I use it, I thought that it would make sense to find something on the quieter side, but was wondering if anybody has used them?
Sounds similar to the hand pinch from a retracting jack stand!:LOL:
I've got some Ingersoll air tools, I think they are very good quality!!! Never had any trouble with them, just put a drop or two of oil in them as with any air tool.....
I spent the big bucks on the Dynabrade air tools for two reasons, one I use the heck out of a DA and my buffer, and two, they fit my crippled old hands better then most other air sanders which means I can work a bit longer.....
i would spend the money for a palm type one the cps and ingerols are top heavy and for me are hard on my hands over the years like dave said my hands have been used hard and if you can not hang on to it you are just not getting any thing done
Oh yeah, thanks Pat! I forgot that part! I won't use anything but a palm type DA, so much easier on the hands.... Even if your hands are strong and healthy now, the two handed DA's are tough on them!!! I kind of do things backwards, though.... my DA's are all palm type, and my polisher is a two hander.... Just works out better for me.....
Well after tons of advice and a lot of thought I started bidding on a used 6" Dynabrade sander with a 3/16" orbit. Every auction would reach the 90 to 100 dollar mark which seemed way to much for a used sander, some of which were fairly beat up. Something about what Dave said, his Dynabrade being nice for old tired arms rang a bell with me, so I found a new one with no reserve and bid on it. I won that earlier this week, 87.00 in the last 30 seconds jumped to 118 but will be worth it in the end(these go for 199-250 new depending where you look), as I plan on doing lots of body work and probably will have more projects in the future.
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