Head gasket removal technology

[JohnHupp]

In past projects, I have used a number of methods to remove gasket material. I'm having a fresh look at the question as I ease back into an engine repair that I started several months ago. I also want to get this right on the first try -- I replaced a valve cover last year with RTV, not long after that went on a long trip, and it started leaking (perhaps not enough cure time). I ended up redoing the job with an OEM pre-formed gasket, but only after a mighty struggle trying to free the cover. The RTV was holding on for dear life in every spot except where the leak was. So as I prepare this block for reinstalling the head, I don't want something like that scenario again.

The FSM says:
Using a gasket scraper, Scotch Brite Pads and Disk (3M Clean 'N Strip 2 in. D x 1/2 in. W x 1/4 in. center hole) remove all the gasket material from the cylinder block, oil pan, rear seal carrier, and front cover surfaces.

But I'm having a hard time pinning down a match for that at 3M. Following is the portal for all the candidates. Of the four categories, I'm confident that I'm not looking for a wheel, but probably something under that first choice for Scotch-Brite Discs:
http://solutions.3m.com/wps/portal/3...bePZBKJFSK8Ggl

But clicking on that still leads to a bunch of choices. I'm guessing the FSM may be indicating one of the "surface conditioning" products, and probably not something with a Roloc attachment since it says "1/4 in. center hole."

But apart from what the FSM says, I saw another post here where someone liked the Roloc bristle brushes for this job (with white, green or yellow pad). So I'm interested in what you think about the alternatives.

That brings me to another question which the FSM manual doesn't even raise -- what "grade" or "grit" to select in any of these given pads.

Obviously there will be more than one way to get this done, but if I'm going to buy something, I want to get something that will do a nice job without scratching the mating surfaces.

[blue92]

I think I used a gasket remover from Permatex once. Worked real good, but dont get the stuff on your skin.

[OldNuc]

Acetone, green scotch brite, 1 1/2" spring blade putty knife after the edge has been sanded to a bevel.
If you are going to have the block boiled out then just strip it down and ship it off.

[bountyhunter]

Single eded razor blade held perpindicular to the surface to scrape and a lot of patience. Scotchbrite pad to polish the surface. Steel scrapers will gouge the aluminum and make a mess of it.

[JohnHupp]

Originally Posted by OldNuc

Acetone, green scotch brite, 1 1/2" spring blade putty knife after the edge has been sanded to a bevel.
If you are going to have the block boiled out then just strip it down and ship it off.

Do you mean "green scotch brite" as in the common scotch brite rectangular pads, or one of the round, mounted automotive pads?

I'm already expecting that I'll need to have the block pressure-tested since I found a corroded head bolt. What's a ball-park price for having a block boiled?

[OldNuc]

If you had water in with a head bolt then pull the engine from the car and strip the block of all removable parts except the oil gallery plugs and start calling shops to get a price to hot tank, pressure test and measure your block. Should be about $50.00 The square green pads work just fine. Send all the aluminum parts to the hot tank, does not materially increase teh price and makes assembly much more pleasant.

[JohnHupp]

Originally Posted by OldNuc

If you had water in with a head bolt then pull the engine from the car and strip the block of all removable parts except the oil gallery plugs and start calling shops to get a price to hot tank, pressure test and measure your block. Should be about $50.00 The square green pads work just fine. Send all the aluminum parts to the hot tank, does not materially increase teh price and makes assembly much more pleasant.

Thanks, OldNuc. If I'm going to have a shop do that work, do I still need to remove the gasket material, or does all that come off nicely in the hot tank?

And if I'm going to replace valve guide seals in the head, is there any reason not to put that in the tank also?