Media blasting carburetor or parts; yes or no

[ericheath]

I would think you would need to be careful with any chemicals that may start consuming the aluminum as it would start enlarging jet holes, throttle bores etc. acids used in chemistry are amazing in how they 'eat' away equally at all. The example was a penny. It was taken down to a sliver thickness, but you could still see Abe, the memorial, and read all the lettering. Short times might be okay.

[Whiskerfish]

SNIP
Please help me out here as I am unsure of the reasoning for making the surface bright when it never was from Honda.

However if a customer wishes the finish to be brighter we can do that for him/her upon request.

Pistol

I know you have GL1800's in the family so you should know about "Safety Chrome"

[Old Fogey]

There's an article in the latest VJMC magazine about vapor honing.


About $3000 for the smallest unit, would take a lot of carbs to pay for it.

Many years ago when I was an apprentice toolmaker, we had an Aquablast (vapour blasting) unit that I used many, many times when building our racing Triumph engines.
Although not as aggressive as some forms of blasting it still removes surface material.
The original finish on Honda carbs is, I believe, some form of passivating; probably a dichromate dip which gives a surface like anodising. Once that surface is knocked off, either by wear and tear or by blasting, you are back to the base aluminium/zinc alloy which will weather and stain unless you coat it with something else.
Re-anodising might be an answer. It doesn't change the dimensions in any way; simply converts the surface to to a hard oxidised layer which can be stained any colour you like. Clear would be the obvious choice, but - colour matched carbs anyone?

[salukispeed]

If I remember correctly When I worked for Honda as A youngster 40+ years ago My Service rep claimed the surface on the Zinc/aluminum Kehin carbs was the result of some sort of Pickeling process that added a bit of sealing quality and oxidation protection and was quite against many of the chem dips of the day. This sealing process helped keep the fresh finish and the fuel stains to a minimum. 40+ years later this hardly matters but is there something similar.

[Old Fogey]

If I remember correctly When I worked for Honda as A youngster 40+ years ago My Service rep claimed the surface on the Zinc/aluminum Kehin carbs was the result of some sort of Pickeling process that added a bit of sealing quality and oxidation protection and was quite against many of the chem dips of the day. This sealing process helped keep the fresh finish and the fuel stains to a minimum. 40+ years later this hardly matters but is there something similar.

Yup, that's exactly what I thought. I served my time in Veeder-Root, an American firm that made/makes? the counter heads for fuel pumps. We used a process like that for the Zamak side frames to prevent corrosion. It put the same sort of iridescent sheen on them that you see on new carbs. Unfortunately, the dipping plant was not some place I had access to, nor any interest in, at that time.

[pistolpete]

If I remember correctly When I worked for Honda as A youngster 40+ years ago My Service rep claimed the surface on the Zinc/aluminum Kehin carbs was the result of some sort of Pickeling process that added a bit of sealing quality and oxidation protection and was quite against many of the chem dips of the day. This sealing process helped keep the fresh finish and the fuel stains to a minimum. 40+ years later this hardly matters but is there something similar.

Yup, that's exactly what I thought. I served my time in Veeder-Root, an American firm that made/makes? the counter heads for fuel pumps. We used a process like that for the Zamak side frames to prevent corrosion. It put the same sort of iridescent sheen on them that you see on new carbs. Unfortunately, the dipping plant was not some place I had access to, nor any interest in, at that time.

Salukispeed and Old Fogey

A friend who is a retired metallurgist also stated the same thing and mentioned Zamak has a similar process. If the treatment is the case and the surface is broken from corrosion or media blasting, the base material can and will degrade much faster.

Pistol

[pistolpete]

One further observation that has been mentioned by Whiskerfish, 50% or more of the total surface of the GL1000 carburetors are machined. Even though ultrasonic cleaning is the best way to clean all of the surfaces, a close watch of the cleaning media must be carefully selected. Most are alkaline based and if to strong it can degrade the machined surfaces as well as the external surfaces.

Pistol

[pistolpete]

To all:

Here is a set of GL1000 carbs that we are currently finishing. Up front I will mention that the external finish was pretty well preserved. When we cleaned them with our two processes the overall improvement was pretty dramatic even with a reasonable starting point.

The brass comes out looking like this every time with our tarnish/degrease process.
Let us know what your opinions are on the carb finish. It is very close to original after cleaning them.

[zman]

They look great to me.

[Old Fogey]

Yeah, they look good.

Every set I've had recently has had serious rust problems on the shafts and linkages. The local plater shop has decided he doesn't want to know about fiddly little old motorcycle parts, so I'm now having to look into plating them myself.

If anyone has tips on this I would be most grateful.

[Old Fogey]

Can't edit a post on this forum, for whatever reason?

I wanted to add; a vinegar bath gets rid of the rust nicely. Takes a couple of days, but no harsh chemicals to worry about.
It also seems to get rid of any cad plating too! I dropped a couple of choke plates in and hey came out clean steel. Going to have to plate them too now. But not cad. Home cad plating is impossible, and in fact there are very few plating shops that will do it either, due to the toxicity.

[pistolpete]

Can't edit a post on this forum, for whatever reason?

I wanted to add; a vinegar bath gets rid of the rust nicely. Takes a couple of days, but no harsh chemicals to worry about.
It also seems to get rid of any cad plating too! I dropped a couple of choke plates in and hey came out clean steel. Going to have to plate them too now. But not cad. Home cad plating is impossible, and in fact there are very few plating shops that will do it either, due to the toxicity.

If you can wait for the postal service I would be happy to send you a few.

Pistol

[Old Fogey]

Your offer much appreciated Pete, but these were just a couple of spares that I was experimenting with so no problem there.

[pistolpete]

Your offer much appreciated Pete, but these were just a couple of spares that I was experimenting with so no problem there.

Very well
Anytime I can help, just let me know.
Pete

[salukispeed]

looks very nice to me.