Stainless steel cup brushes

[jdt1986]

Does anyone know where to get the stainless steel cup brushes crimped not knotted and also the 1/4" shank stainless wire wheel like you would use in a
die grinder i am doing alot of aluminum castings for boats (transom brackets,power head cracks,skeg repairs,)i would like to buy a few but lws supply charged me 30 bucks for one 3" cup brush crimped (weiler brand) that seems a little steep to me just wondering thanx in advance.

[acourtjester]

I don’t know if I would use a die grinder with a wire wheel. It may over rev and throw off bullets also no guard. [I am assuming your talking air powered.]
And the crimped type wheel has a much lower speed rating (4500)
You may try the poly-carbide abrasive wheels they are still low rpm but have a wider face for cleaning.
The SS knotted type wheel has a much higher rpm rating (12000) and are cheap at HF.
A 4-1/2" electric angle grinder with a knotted SS wire wheel and a guard will clean lots of aluminum.

have fun
Tom

[Timberwolf]

You should never use a powered wheel to clean off aluminum like this. You will just rub the oxides into the surface and be hurting yourself. You need to use a hand brush to remove oxides then clean it with acetone or alcohol.

[jakeru]

Harbor freight has 3" amd 4" diameter, crimped stainless steel cup brushes with a 5/8"-18 (angle grinder) mounting nut. They are in red cube-shaped boxes, and they are a great price for a stainless steel cup brush. $4-$5 regular price sticks in my mind. Last time I saw them, they were on clearance with the yellow tag, I think about $3 each, so could be going away, or coming back with a different style of box (and probably a higher price), like a lot of other HF items currently on clearance.

Here I found them online:
http://www.harborfreight.com/3-inch-...ush-45651.html
http://www.harborfreight.com/4-inch-...ush-45650.html

But, I agree using them to prep aluminum may have too much power, and end up folding oxides under the surface. If you are "smearing" the surface when prepping aluminum, it's generally not good. This happens when you get the surface of the aluminum too hot. You can identify "overheated/smeared" surface as "mottled" (irregular looking). You'll see what we mean if you try and weld an aluminum surface like that. It will not weld clean. If you use a powered cup brush to prepare aluminum, do it with low RPMs. Maybe hook it up somehow to a variable RPM hand drill. They do have variable speed angle grinders (that are marketed for rock polishing, etc) that would be ideal for using these cup brushes on aluminum.

Another option, that is pricey, but I would look into is a roloc bristle disc. They are actually really expensive, but work very well. Here is what they look like:
The flexible teeth conform to an irregular surface very well.

There are other plastic abrasive-impregnated bristle abrisive brushes that work possibly as well for less money. Harbor freight sells some I have used with some success. Last time I used them however I was not getting a good result, I'm not sure why. They are not super fast but do conform well through irregular surfaces. You don't want to get the plastic teeth so hot that they melt.

I use the nonwoven scotchbrite pads quite a bit. They work well for flatter sufaces, at least initially. They do tend to load up and need to be flushed clean (such as with solvent) or replaced kind of frequently. Solvent clean afterwards is necessary.

If you have a thick enough aluminum surface to prepare that can withstand some material removal, methods like carbide burr are very effective. Generally can weld immediately after (if no excessive airtool oil got blown on the surface.)

I don't find stainless hand brushes effective in removing thick aluminum oxides, which can be very tough stuff. They are perfect good for abraiding light oxide layers, like the mill scale on brand new, fresh aluminum stock.

Just my 2c. Probably every welding will have their own ways. I just picked up some chemical (acid based) aluminum cleaner I'm looking forward to trying sometime. Supposedly just spray or brush on, wait a bit then wipe it off, and ready to weld. So far none of the acid cleaners I tried worked well on aluminum, but this will be the first one I will have tried specifically made for cleaning aluminum for weld preparation. It has some extra fancy ingredient in it. Will see, next time opportunity arises.

[parkour]

Timberwolf;

Would simply being very gentle and not applying much pressure at all with a powered tool work?
What about using an ultra fine scotchbrite pad, powered or unpowered?
What diameter of wire SS brush would you recommend?

I would also throughly clean the alum before brushing to prevent further contamination of the alum, or contaminating the brush.... then brush, and clean again.

[jdt1986]

Also looking for the carbide burrs both single and double cut that is actually what i use to primaraly clean the surface and v out the area to weld . Jakeru have u had good experiences with the harbor freight brushes? I didnt even think to check there it slipped my mind.
As far as smearing the surface it doesnt really do that (in my experiences) i also do extruded aluminum repairs the wire wheels does a great job(no specs of impurities in the puddle while welding its like a mirror). On a side note i also checked on a weldcraft wp 20 on arc zone the pro 25 is 300 bucks and i just cross referenced all the part numbers on ebay and a weldcraft brand torch with weldcraft or miller brand power,gas and argon cable and hoses came out to 138 bucks thats all rubber and 25'. Has anybody else done that? The blue ever last torch is beefy and on castings espcially blocks it really keeps its cool but when i do stainless steel boat railings its kind of big and cumbersome. Also thanx for the replies and the help and advice. One more thing has any body tried the deluxe or equivalent gas lens kit for arc zone its on my wish list . Ebay also has cheap gas lens parts but their from overseas didnt know if the price difference would b worth taking a risk. Thanx alot

[jakeru]

Also looking for the carbide burrs both single and double cut that is actually what i use to primaraly clean the surface and v out the area to weld . Jakeru have u had good experiences with the harbor freight brushes? I didnt even think to check there it slipped my mind.
As far as smearing the surface it doesnt really do that (in my experiences) i also do extruded aluminum repairs the wire wheels does a great job(no specs of impurities in the puddle while welding its like a mirror).

A mirror is good! Whatever you are doing for prep then , it is working well. A mirror puddle, and no porosity in the deposited weld bead is what it's all about.

I know that wire brushes with smaller wire diameters are a lot "gentler". They come in all different wire diameters, brush diameters, bristle lengths (longer bristles = more flexible and conformable, less aggressive.) They conform to the surface with less pressure. That can have a lot to do with whether it smears or not. You basically want a soft, long bristled, small wire diameter brush, run wihtout excessive surface speed, so it removes any "crusty junk" off the surface of a metal (especially soft aluminum) without really abrading into the parent metal.

The HF cup brushes are OK, but not really made for super high RPM. If you are using with an 11k RPM angle grinder I would get the 3" cup diameter rather than the 4", the smaller diameter cup brush will be less likely to spit wires at you. Ideally you'd have an angle grinder that could go lower RPM yet for those brushes, IMO.

[parkour]

Ah, this is funny.

You could run your angle grinder on 12 volts (like from a battery or battery charger) and it will run ~1/10 of the speed it would at 120 volts. It is close to aggression of a hand brush, but without having to actually do it yourself... that's if the angle grinder is too aggressive at 120 volts.

Just as an aside, I am not joking. An angle grinder uses a series wound "universal" motor. It can run on AC or DC. Using a battery or battery charger is a simple way of getting lower voltage so that it will run more slowly.