Roloc Bristle Discs

[JDon99]

In the middle of doing iron cylinder heads on my Silverado and wanted to try these out. Which color would work best for iron heads? I take it that these don't actually contain an abrasive, correct? Thanks.

 

[ZRX61]

They do contain abrasive, I wouldn't use one on a cylinder head or any other gasket surface.

 

[BillK]

Don,
Use a sanding block and 100 grit sandpaper. Or even better a 2" x 6" knife sharpening stone. I have seen way too many cylinder heads ruined by guys using disc type cleaners. I don't care how good you are, there is no way to keep from getting low spots with them. If it will remove gasket material, it will remove metal. Simple as that.

If it had leaking head gaskets, your best bet is to have your machine shop resurface them. The factory finish is terrible. Not saying that because I own a machine shop, only because it is the truth.

 

[JDon99]

I had to pull the heads to get some broken exhaust manifold bolts out(snapped extractor off, so I ended up pulling the heads and welding nuts to get everything out). I guess I'll just clean everything with a razor instead of using the bristle discs. Thanks fellas.

 

[Fedwrench]

Green are coarse, yellow is medium, & white is fine and great for aluminum.

 

[lilcraigford]

Green are coarse, yellow is medium, & white is fine and great for aluminum.

To add to what was said:

Green - 50 Grit
Yellow - 80 Grit
White - 120 Grit

I recently purchased a 1" yellow bristle disc and arbor to try out on an aluminum block and head. I will not be using these on gasket surfaces, but for cleaning (removing oxidation) and prepping the castings for paint.

 

[Farmall 1066]

Used mostly green for cast and white for aluminum. Love that they last forever and work great.

 

[TK-421]

So someone educate a noob, why are the bristle discs not good for gasket surfaces? Even the white one removes too much material to make a smooth bond?

 

[Ole Slewfoot]

I think its harder to be even with the little ones. I wouldn't worry much about my 4"er on an iron head, but I'd probably alternate with a scraper for removing bulk.

 

[Mgnu]

We need a "Rolocs of Garage Journal" thread. 3m doesn't make it easy to navigate, and I think there just might be about a billions Roloc SKUs.....

 

[bobcatdan]

I never clean the sealing surface of a head because it's going to the machine shop to be checked and surface . Working on almost all cast iron blocks, I have cleaned many top of blocks with the yellow ones. Light pressure, going over it evenly and taking my time. Big thing is cleaning afterwards. Getting all the debris off the block. I have done many head jobs with no failures afterwards to my knowledge.

 

[Ole Slewfoot]

We need a "Rolocs of Garage Journal" thread. 3m doesn't make it easy to navigate, and I think there just might be about a billions Roloc SKUs.....

I'd be real interested in a better way to buy the brake prep discs than the dozen pack.

 

[daddy2coull]

i've used the roloc brown cookie discs to clean iron heads and blocks for the last ten years or so. never had a problem.

 

[Tony G]

I've had no problems with roloc discs. However if you are worried about taking off metal you can use a braided steel wire rotary brush attached to a die grinder. They are great on carbon buildup on heads and they don't scratch the head surface. The vertical version not the horizontal brush.