Scotchbrite--------NEVER !!

[bbobynski]

Someone in another thread mentioned using scotchbrite to clean up gasket surfaces during an engine rebuild.....not a good idea....

Scotch brite.......!!!!............?????????

NEVER USE SCOTCHBRITE TO CLEAN UP GASKET SURFACES OF AN ENGINE.

NEVER, EVER, EVER USE SCOTCHBRITE ON AN ENGINE. At least not one you want to run again for a long time.

Scotchbrite seems so benign but it is death to engines. Scotchbrite pads are nylon fibers with 40 micron particles of aluminum oxide in them. Scotchbrite dust leaves behind all those 40 micron particles hidden everywhere. Aluminum oxide is an extremely aggressive abrasive. It imbeds in the bearings and eats the crank....and other things.

Scotchbrite is the bane of the aftermarket re-man engine industry. There are lots of "new" re-mans ruined by cleaning up the old parts with scotchbrite pads and then installing them. Eats up the engine immediately. That is why many engines fail the main and rod bearings after a head job or other work...scotchbrite. People think it is because of coolant getting into the oil ruining the bearings or something when it was really the scotchbrite the mechanic used to clean up the parts... especially a Northstar engine where the block deck surface cleaning funnels the scotchbrite dust down the oil drain back passages.

If you cleaned up parts with scotchbrite you now have a HUGE cleanup job ahead of you cleaning up after the scotchbrite. You must make positively sure that none of the dust remains anywhere on any parts or got into the oil cavity. Hopefully the valley of the engine was covered if you used scotchbrite on the deck surface as if it drifted into the valley or into the pan your engine is toast.

I am very very serious about this. Scotchbrite has a very bad reputation in the industry as it seems like such an ideal cleanup method, seems so benign, yet can cause such extreme damage. Most mechanics in the know stay miles away from scotchbrite as it is harder to clean up after it than any labor it saves.


If you doubt this at all call JASPER or any of the main engine re-man companies and ask them if it is OK to use scotchbrite to clean up the manifold you are going to put on your Jasper re-man....

 

[427Z06]

I use Permatex gasket remover and a putty knife. You have a better way?

 

[JohnBrowning]

AC/Delco and GM both have had huge issues with this! The bearings will look like someone took sand paper to them and sanded them down tot he copper! Deep groves in the bearing that you can catch a thumb nail on!

 

[bbobynski]

ANYWAY is better than scotchbrite pads or polishing discs. I have seen a LOT of engines ruined this way with aluminum oxide contamination from scotchbrite pads. Many field return cores of brand new re-man engines that were returned to the re-man center had bearings fail due to the mechanic cleaning up the old intake for installation onto the re-man long block with scotchbrite and then not cleaning up sufficiently.

I like a razor blade scraper and some sort of chemical gasket remover to soften the old gaskets. Just do NOT let scotchbrite get anywhere near the engine or use scotchbrite in the area so that the dust can settle in the engine unknowingly.

 

[bbobynski]

Honestly, it depends on when you catch the failure as to what the failure looks like. When the aluminum oxide particles get into the engine they are too large for the bearing clearance and imbed into the soft bearing surface due to the pressure of the crank journal. The bearing will look perfect, absolutely perfect...and the engine will actually run fine for quite a while. Right up to the point that, due to heat/load/RPM the oil film is pressed so thin that the peaks of the aluminum oxide peek thru the oil film and touch the crank....and start machining it down. In 20 minutes the crank journal will feel like a phonograph record surface yet...THE BEARING WILL STILL LOOK PERFECT. You would have to look at the bearing shell under and SEM to see the abrasive particles imbedded into the bearing. Run the engine harder and at more RPM/heat/load and the grooved up bearing looses so much load capacity that it starts to eat into the bearing shell surface due to metal-to-metal contact due to the oil film collapsing becasue the surface area of the grooved surface has been destroyed. THEN the bearing shell looks grooved up...but this is right before it seizes up/spins a bearing and puts parts thru the side of the block.

Trust me, I have seen this exact failure mode many many times as scotchbrite is a favorite "tool" of the unknowing. Often, when a reman or repair fails the mechanid blames the reman or the "glycol in the oil" or whatever never knowing that it was the scotchbrite pad he used to clean up the manifold surfaces before reasembling.

 

[antilles56]

i have seen intake manifolds replace and the techs will use the "approved by gm" cleaning cookie, and the car will come back on the hook in less than 1000kilometers
with the engine knocking so badly you would think that the rods are comming out the sides.

the oil filter was sent out to a local lab here in toronto
and the results came back showing silica and alumina carbide levels approaching 10%..........needless to say the stealership would have the buy a new engine.
even the dust comming off these scotch pads will cause
severe engine damage

 

[srivett]

How about other abrasives? After using a razor blade I use sandpaper and then clean everything off with kerosene. It is sooo tough to keep things clean if you aren't working on an oil pan gasket area which is facing down.

Thanks, Steve

 

[Gary Allan]

Well, my engine builder friend stopped using Scotchbrite after attending a engine builders seminar thing at Indy a couple of years back ..but that wasn't what they mentioned as the reason. They cited creating divets in the bolt holes in the deck and head. I forget the particulars of what issues this brings up ..but I'm sure that some gasket/head warpage (however minor) was the result of it.

Not that I doubt your conviction on this topic but this wasn't some "hillbilly howdown" that he attended ..so I'm surprised that this aspect of the use of Scotchbrite wasn't added to the warning.

He had, btw, used Scotchbrite for most of his rebuilds for the local bracket racer and stock car crowd before learning this. He never had one blow...get tired (bi-annual refresh) ..yes, but never grenade.

Thanks for the advice! I'll add this to his list of reasons not to use it.

 

[JohnBrowning]

I had a draw full of them I used to hand out to people as desk ornamanets! I used a bad Mahl piston as my candy dish!

 

[labman]

Just because I have gotten away with limited use of the pads, doesn't mean it is a good idea. I will rethink this.

 

[XS650]

quote:

---

Originally posted by srivett:
How about other abrasives? After using a razor blade I use sandpaper and then clean everything off with kerosene. It is sooo tough to keep things clean if you aren't working on an oil pan gasket area which is facing down.

Thanks, Steve

---

Sand paper isn't good either. It has aluminum oxide or worse particles in it.

Detergent and water works much better than kerosene for floating crap out of the pores in the metal. Hot detergent scrub down, hot water rinse, then a coating of light oil or other rust retardant.

 

[eljefino]

Correct me if I have heard wrong, but german cars mostly pump oil through the crank and bearings before it gets to the filter. Their philosophy is "better dirty oil than no oil". Other makes filter the oil first before it touches anything else in the motor. Would this make a difference? Seems the oxide particles are big enough to get filtered.

 

[widman]

I would ban scotchbrite if I could. An idiot used it to wash my BMW. There is no amount of polishing that can get rid of the scratches.
-At least put a big wanting on it in 10 languages: "NOT FOR USE BY STUPID PEOPLE"

 

[srivett]

My friends dad used an S.O.S. pad to remove bird poo from his car. Strange thing is that it removed a lot of his paint in those areas too.

Cheers, Steve