Aluminum cleaing

[Jim D.]

Have a 67 327 L79. Would like some ideas on cleaning and refinishing the aluminun intake and finned valve covers. Is glass bead blasting ok followed by lite alumablast paint and high temp clear clear? What are you guys doing with aluminum?

[Timothy B.]

Re: Aluminum cleaing

Jim,

This has been discussed and info is in the archives. The short of it is that glassbeading is a no no and will destroy the original finish.

The people that restore these items don't really tell the procedure except that the equipment used is expensive. Be careful with glassbeads..

[Ray G.]

Re: Aluminum cleaing

Have a 67 327 L79. Would like some ideas on cleaning and refinishing the aluminun intake and finned valve covers. Is glass bead blasting ok followed by lite alumablast paint and high temp clear clear? What are you guys doing with aluminum?

Hello Jim;

Agree w/ Tims thoughts on glass or other type beading.
Paint strippers and lacquer thinner do a nice job without damaging the original "skin" appearance.

Good luck w/ your restoration.
Ray

[Edward J.]

Re: Aluminum cleaing

Have a 67 327 L79. Would like some ideas on cleaning and refinishing the aluminun intake and finned valve covers. Is glass bead blasting ok followed by lite alumablast paint and high temp clear clear? What are you guys doing with aluminum?

Jim, short of re-skining the manifold and valve covers(as Tim say costly), after almost 50 years the loose the coating anyway, the elements and gasoline and oil stain them, I can tell what I Did , I just rebuilt the engine and gave the intake and valve covers to the machine shop and he put them in the clenaing solution and let them sit for about 4/5 days and they came out looking like new,Less the coating of coarse, the solution is a citric solution these days and is a enviromentaly friendly. My valve covers were painted and it removed the paint.

So I posted a question on the intake about the dull aluminun paint that was used along the edges of head and intake and themostat, It appears that the intake was with covered quite a bit of paint anyway, you just used a high temp clear and lightly coat the rest.

Buy the way my car is a small block 327/340 so take it for whats it is worth. But there will be a small deduct on the finish if the car is judged. The way I look at it is, The cost of restoring a car today is expensive, alittle paint here and there will look good and will keep the costs down a little.

[John H.]

Re: Aluminum cleaing

Jim -

I've never seen a clear that didn't yellow, especially on the heat crossover ports at the center on each side; then you get to start all over again.

[Don H.]

Re: Aluminum cleaing

My recommendation is re-skinning for both aluminum intake manifold and valve covers. Re-skinning is a gentle tumbling process that takes the parts back to the same as new condition, except of course will not affect nicks or dinks in fins, etc. Re-skinning is not expensive. J & P Precision Deburring in Chatsworth CA does a pair of aluminum valve covers for about $25 and an intake manifold would be about the same. They did my valve covers about 18 months, (about 1000 miles) ago and the appearance today is the same as it was right after the tumbling process.
For my intake manifold, I used paint stripper to remove all paint, and then painted on Naval Jelly for Aluminum, let sit 10 minutes, hosed off, and the manifold sparkled like new. Happy !

[Matt L.]

Re: Aluminum cleaing

i agree with don. my parts were also tumbled. they came out beautiful.we did the valve covers, intake base,plenum,lid,expansion tank,alternator housing,and a few other misc pieces.
take care,
matt

[Joel F.]

Re: Aluminum cleaing

My recommendation is re-skinning for both aluminum intake manifold and valve covers. Re-skinning is a gentle tumbling process that takes the parts back to the same as new condition, except of course will not affect nicks or dinks in fins, etc. Re-skinning is not expensive. J & P Precision Deburring in Chatsworth CA does a pair of aluminum valve covers for about $25 and an intake manifold would be about the same. They did my valve covers about 18 months, (about 1000 miles) ago and the appearance today is the same as it was right after the tumbling process.
For my intake manifold, I used paint stripper to remove all paint, and then painted on Naval Jelly for Aluminum, let sit 10 minutes, hosed off, and the manifold sparkled like new. Happy !

Good info, thanks!

[Michael F.]

Re: Aluminum cleaing

Jim -

I've never seen a clear that didn't yellow, especially on the heat crossover ports at the center on each side; then you get to start all over again.

I agree. Even hi temp clears yellow. Forgo the clear and just use flat aluminum hi temp paint. VHT makes a "flat aluminum" that is hard to tell from a non painted aluminum piece.

[Domenic T.]

Re: Aluminum cleaing

I haven't seen a re-skin, only in aircraft restoration.

The intake was originally SAND cast and I would think tumbling would take the effect of the sand casting away because it tends to smooth the surface.

I would agree that SAND blasting is a little harsh on the surface but I can't see where glass bead (which is just about powder) can hurt the already rough surface.

I also soak aluminum in chemical and find when the aluminum is corrosion stained it has to be removed by powder blasting.

This re-skinning secret in my opinion is more scam than secret.

Why the secret???

DOM

[Don H.]

Re: Aluminum cleaning

Re-skinning is no scam, and no secret. The name is a little odd, because to me it implies that some kind of new "skin" or surface is applied. Nothing new is applied. Maybe if you called it deburring it would make more sense.
I can tell you that in the opinion of many, a gently tumbled surface treatment, or re-skinning, creates the smooth egg shell like finish that is what original should be like (if it isn't).

[Domenic T.]

Re: Aluminum cleaning

Re-skinning is no scam, and no secret. The name is a little odd, because to me it implies that some kind of new "skin" or surface is applied. Nothing new is applied. Maybe if you called it deburring it would make more sense.
I can tell you that in the opinion of many, a gently tumbled surface treatment, or re-skinning, creates the smooth egg shell like finish that is what original should be like (if it isn't).

Don,
Makes sence but I'll bet they beed blast if they are going to tumble afterwards.

I have a parts tumbler in the shop and it does not remove the black corrosion spots on the aluminum.
.
My tumbler to small to put large parts in and we use walnut shells most of the time.

I use the tumbler to polish parts (die cast) and give them the sheen they had when they were new and think that tumbling a sand cast part changes the original sand cast look.

There is a acid we use on aircraft sand castings and skin, all aluminum with exception to anodized aluminum. It does a good job on cast and can be further treated with clear alodine which is a chemical not a paint, that slows or stops further corrosion.

DOM


W

[Michael F.]

Re: Aluminum cleaning

Don,
Makes sence but I'll bet they beed blast if they are going to tumble afterwards.

I have a parts tumbler in the shop and it does not remove the black corrosion spots on the aluminum.
.
My tumbler to small to put large parts in and we use walnut shells most of the time.

I use the tumbler to polish parts (die cast) and give them the sheen they had when they were new and think that tumbling a sand cast part changes the original sand cast look.

There is a acid we use on aircraft sand castings and skin, all aluminum with exception to anodized aluminum. It does a good job on cast and can be further treated with clear alodine which is a chemical not a paint, that slows or stops further corrosion.

DOM


W

It's hydroflouric and phosphoric acid. All it takes to neutralize is a soapy water mixture.

[Michael F.]

Re: Aluminum cleaing

I haven't seen a re-skin, only in aircraft restoration.

The intake was originally SAND cast and I would think tumbling would take the effect of the sand casting away because it tends to smooth the surface.

I would agree that SAND blasting is a little harsh on the surface but I can't see where glass bead (which is just about powder) can hurt the already rough surface.

I also soak aluminum in chemical and find when the aluminum is corrosion stained it has to be removed by powder blasting.

This re-skinning secret in my opinion is more scam than secret.

Why the secret???

DOM

The secret is they make too much bucks reskinning to to tell you how easy it is. You hit the nail on the head in your description.

[Tom R.]

Re: Aluminum cleaing

This has been discussed and info is in the archives. The short of it is that glassbeading is a no no and will destroy the original finish.

I know of an NCRS Restorer who reduces the pressure to, I believe 30# and it cleans without destroying I guess the texture.