re-finishing my bellhousing on my 68 I blasted it, now what is the correct finish?PIC

[Stan E.]

Re: re-finishing my bellhousing on my 68 I blasted it, now what is the correct finish

I used Strip-Eze,paint remover, on mine.

[John D.]

Re: re-finishing my bellhousing on my 68 I blasted it, now what is the correct finish

I can't tell you how many AIR pumps and alternators I have judged that I took a finish deduction because they have been "blasted." I no longer discuss what kind of "blasting" was done. If it is not TFP then finish = -20%.

I see so many blasted aluminum pieces I am beginning to think few people will know what a die cast aluminum piece looks like. I just cringe when I read these kinds of threads.

Be careful.

Terry, I agree with you 100%. I thought for sure that by 2009 guys would quit blasting all the aluminum castings. So many places out there to send the castings for refinishing. FI's come in the door here that were blasted with very course media, blasted tags, etc. Then the owners expect a miracle. JD

[Michael H.]

Re: re-finishing my bellhousing on my 68 I blasted it, now what is the correct finish

So, you're thinking my bellhousing had been re-painted before?

Brandon,

Yes, the housing that you show in your first post has definitely been repainted. No doubt.
It would be very unusual to see that much/complete of a coating that far to the rear of any housing, no matter which engine assembly plant did the painting. The coating, if ever that far to the rear, would typically be a mist coat and not a full on direct hit.

The big giveaway on your housing, however, is the fact that the area under the bolt heads and in the drilled holes for housing to engine attachment are also showing a lot of orange. That wouldn't be possible if the housing was attached to the engine when it was painted.

[Brandon T.]

Re: re-finishing my bellhousing on my 68 I blasted it, now what is the correct finish

Brandon,

Yes, the housing that you show in your first post has definitely been repainted. No doubt.
It would be very unusual to see that much/complete of a coating that far to the rear of any housing, no matter which engine assembly plant did the painting. The coating, if ever that far to the rear, would typically be a mist coat and not a full on direct hit.

The big giveaway on your housing, however, is the fact that the area under the bolt heads and in the drilled holes for housing to engine attachment are also showing a lot of orange. That wouldn't be possible if the housing was attached to the engine when it was painted.

Good way to look at it, Joe if you see this post of Michael's what is your take on it? I kinda agree with him.

[Joe L.]

Re: re-finishing my bellhousing on my 68 I blasted it, now what is the correct finish

Good way to look at it, Joe if you see this post of Michael's what is your take on it? I kinda agree with him.

Brandon-----


I see little paint on the bolt head interface surfaces, but that may have just been "galled away" by the friction of the bolt head. As I look closer at the photos and from what I can see, it looks like there might be paint INSIDE the bolt holes. If that's the way it actually is, then I would agree that this could not be the original paint.

A few things surprise me, though: first, if the bellhousing was previously painted post-factory, then someone went through the trouble of stripping off all the original paint first since I don't see any evidence of "over-paint". Second, and most important, the shade of Chevrolet orange that was used looks to me to be just about exactly that used at Tonawanda in the 1968 period. The majority of aftermarket Chevrolet orange engine paints available, particularly years ago, were pretty far off from what was used at the engine plants. This includes the GM-supplied Chevrolet orange.

How does the paint on the engine compare to the paint on the bellhousing?

[Keith L.]

Re: re-finishing my bellhousing on my 68 I blasted it, now what is the correct finish

Brandon, here is my 70.

[Joe L.]

Re: re-finishing my bellhousing on my 68 I blasted it, now what is the correct finish

Brandon, here is my 70.

Keith-----


The bellhousing paint pattern pictured here is very typical of Flint-manufactured small blocks. However, Tonawanda-manufactured big blocks typically have more paint coverage on the bellhousing, up to including coverage of the entire bellhousing. Typically, though, the Tonawanda painting left a small amount of unpainted bellhousing at the transmission mounting end.

[Ridge K.]

Re: re-finishing my bellhousing on my 68 I blasted it, now what is the correct finish

Terry and John bring up a pretty good point.
I simply spayed a little degreaser on my '67 bellhousing. Then powerwashed. It cleaned up perfect, and did not disturb the "skin" from the casting process.

[Brandon T.]

Re: re-finishing my bellhousing on my 68 I blasted it, now what is the correct finish

Terry and John bring up a pretty good point.
I simply spayed a little degreaser on my '67 bellhousing. Then powerwashed. It cleaned up perfect, and did not disturb the "skin" from the casting process.

I hear people mention skinning etc..

when you can blast an aluminum piece to death and when you're done it will look DULL...clean but DULL.

you then can get some steel wool and buff it and that will bring back what you guys are calling the skinning...

here is an exmaple of the before and after of my intake manifold that I blasted...then buffed with steel wool. Look and see if yo ucan tell I blasted it or it looks like it was sent off to be re-skinned in a tumbler...I can't tell the difference.

In my OP it's not like aluminum pieces on these cars have like a galvanized finish or something so this skinning deal is nothing. Theres nothing on the aluminum thats a sealer or something atleast I don't think so.

before


after


after 2

[Mike E.]

Steel wool and aluminum

Buffing with steel wool after cleaning an aluminum part does NOT in any way, shape, or form, restore the natural-cast aluminum finish and appearance to the piece. There are enough of us that have been around long enough that if that were the case, the word would have gotten out LONG ago. In fact, just the opposite. Many of us have tried that route, determined that it didn't in fact duplicate the as-cast finished, and then wondered what to do.
Believe me, Brandon, you are not corresponding on this board with a bunch of guys who woke up last night and decided that they would restore a Corvette. There are thousands of years of accumulated wisdom in Corvette restoration experience and study amongst the members of this board who regularly participate.

[Brandon T.]

Re: Steel wool and aluminum

Buffing with steel wool after cleaning an aluminum part does NOT in any way, shape, or form, restore the natural-cast aluminum finish and appearance to the piece. There are enough of us that have been around long enough that if that were the case, the word would have gotten out LONG ago. In fact, just the opposite. Many of us have tried that route, determined that it didn't in fact duplicate the as-cast finished, and then wondered what to do.
Believe me, Brandon, you are not corresponding on this board with a bunch of guys who woke up last night and decided that they would restore a Corvette. There are thousands of years of accumulated wisdom in Corvette restoration experience and study amongst the members of this board who regularly participate.

All I can say is my friend sent his intake off to a jerry mcniesh? or something like that for around $175 to be re-skinned by putting it in a tumbler? I was going to send mine when he had his done but just decided to try my luck with it doing it myself.

mine turned out looking IDENTICAL in up-close in person to his and I bead blasted mine and buffed it with steel wool..even the guy that had it done said the same thing.

thats all I'm saying

again guys low pressure and distance..

[Joe L.]

Re: Steel wool and aluminum

All I can say is my friend sent his intake off to a jerry mcniesh? or something like that for around $175 to be re-skinned by putting it in a tumbler? I was going to send mine when he had his done but just decided to try my luck with it doing it myself.

mine turned out looking IDENTICAL in up-close in person to his and I bead blasted mine and buffed it with steel wool..even the guy that had it done said the same thing.

thats all I'm saying

again guys low pressure and distance..

Brandon-----

There are TWO types of castings being discussed here. Aluminum manifolds are a SAND CASTING. As it comes from the mold, a sand casting has a surface finish which I would not describe as a "skin" but it certainly has a subtle but recognizable "patina". Jerry MacNeish does an excellent job of restoring the finish on these manifolds. However, they are not restored to EXACTLY the original appearance; VERY close, but not EXACTLY.

63+ Bellhousings are a PERMANENT MOLD or DIE CASTING. These exhibit a completely different finish. These have the appearance of a "skin" although it's really not a "skin" in the truest sense of the term. Once this sort of surface finish is disturbed by ANY sort of abrasive process, even the mildest form of such a process, I don't know of ANY way to restore it to exactly original appearance.

[Brandon T.]

Re: Steel wool and aluminum

Brandon-----

There are TWO types of castings being discussed here. Aluminum manifolds are a SAND CASTING. As it comes from the mold, a sand casting has a surface finish which I would not describe as a "skin" but it certainly has a subtle but recognizable "patina". Jerry MacNeish does an excellent job of restoring the finish on these manifolds. However, they are not restored to EXACTLY the original appearance; VERY close, but not EXACTLY.

63+ Bellhousings are a PERMANENT MOLD or DIE CASTING. These exhibit a completely different finish. These have the appearance of a "skin" although it's really not a "skin" in the truest sense of the term. Once this sort of surface finish is disturbed by ANY sort of abrasive process, even the mildest form of such a process, I don't know of ANY way to restore it to exactly original appearance.

what is the skinning exactly thats on it then? a sealer like or what?

it's got to be something..if people say it's skinned..what exactly is the skin?

[Joe L.]

Re: Steel wool and aluminum

what is the skinning exactly thats on it then? a sealer like or what?

it's got to be something..if people say it's skinned..what exactly is the skin?

Brandon-----


There is no "skin" or sealer. What there is is the natural appearance of molten aluminum that's solidified against the permanent mold. This results in a very smooth surface which may APPEAR to have a "skin".

Think of it like a big drop of solder. When the molten solder hardens, the surface will have a smooth, shiny appearance. There is no "skin" but it might appear like that to some. If this surface is abraded in any way, there will be only one way of ever making it look like it did when it solidified. That would be remelting it, letting it "drop" and re-solidifying. It's exactly the same way with permanent mold/die cast aluminum pieces. Once the surface finish of the piece AS IT COMES OUT OF THE MOLD is disturbed by any abrasive process and some chemical processes, the only way to exactly restore that finish is to re-melt the aluminum, re-pour it, and remove the piece from the mold. Obviously, that's not practical.

[Brandon T.]

Re: Steel wool and aluminum

I see..

and thats true..just saying with the right set of EYES and taking your time you can blast pieces at low pressure and distance then go back over them with some steel wool and get the piece to look DANG close to original without sending it to someone that re-skins aluminum pieces like say that guy jerry.

because mine turned out looking just like the guy that sent his to jerry...jerry did a great job with his just saying mine turned out the same.