Topic: Painting/spraying cb400/4 engine case

[HondaCB400F]

So I've got to the stage where I need to paint the engine casing on my 1977 Honda cb400 superfour, does anyone have any suggestions as to what process I should choose next? I've seen vapour blasting and loads of other methods of properly cleaning the parts before painting, but I'm not sure which is best. I want it to look as original as possible. Any help would be great!

[innovativems]

Vapor blasting is amazing and the route I go now


Sent from my iPhone using Tapatalk

[MikeSimon]

As far as cleaning is concerned, there are different options available. It depends a little on what you have - bare cases or a lower motor with all internals still in it.
For painting Honda cases, I found marine engine paint the best solution. Evinrude Engine Silver or a similar OM product are best for color match the Honda silver. These paints are sufficiently heat resistant and you do not need to clearcoat them.
I even painted top ends with great results.

[MoMo]

Vapor blasting is amazing and the route I go now


Sent from my iPhone using Tapatalk

and quite expensive     Most any quality high temp paint when properly applied works. I've had good luck with VHT....Larry

[innovativems]

Vapor blasting is amazing and the route I go now


Sent from my iPhone using Tapatalk

and quite expensive     Most any quality high temp paint when properly applied works. I've had good luck with VHT....Larry

I've been using a guy in Michigan that's pretty cheap.  About $200 to do an entire disassembled motor


Sent from my iPhone using Tapatalk

[flybox1]

Acetone wash down before primer/paint.

[BRAD CHIEDUCH]

I agree vapor blasting is the way to go.  It gets into all the nooks and crannies and leaves with a nice finish to either paint or polish.  It cost me around $200 to do my entire engine inside and out which I think is reasonable.  Considering your other options (chemical stripping, sanding etc) vapor blasting is the least labor intensive and I believe gives you the best results.

[MoMo]

I agree vapor blasting is the way to go.  It gets into all the nooks and crannies and leaves with a nice finish to either paint or polish.  It cost me around $200 to do my entire engine inside and out which I think is reasonable.  Considering your other options (chemical stripping, sanding etc) vapor blasting is the least labor intensive and I believe gives you the best results.

Love your avatar........that could be a photo of me in my youth as I've done that but with a screwdriver.  That's why the name MoMo fits

[MikeSimon]

If you do not paint, I would go with vapor blasting. Depending on the material, you may still have to coat to prevent oxidation. If you paint, you can use a less expensive method to clean. A business associate of mine does the whole spectrum of cleaning/finishing from vapor blasting to abrasive blasting to powder coating and painting. I was able to have the top end of my CB750 K'76 vapor blasted for free, otherwise, I would have painted. Together, we have done several projects. The last one we finished was a /2 BMW. You can go overboard with a restoration process if money is not an issue. I would be rather frugal with anything where the final product value will be less than $10,000.-

[Stev-o]

If you do not paint, I would go with vapor blasting.

He wants the stock finish which was paint  [I also love vapor blasting, did it on my Kaw motor which came "naked" from the factory].

+1 on VHT paint, I used the color Aluminum recently on my K4. 
First clean thoroughly with Gunk Foamy Engine cleaner, sand any rough/pealing areas, final clean with acetone and spray. Some guys bake it if the cases are apart, but I didnt.  Turned out great...

[Tim2005]

If you want it really as "original as possible", then take note that on a 400f the original finish was silver paint for the top half of the crankcase with an unpainted lower half of the crankcase.

[HondaCB400F]

So just to clarify this, the top crankcase was silver paint but the rest was just bare aluminium? Where would one go to find this kind of specific information?

thanks for your help! (also thanks to everyone else too!)

[Bodi]

Not sure where this info would be recorded but some of us had new bikes back in the 70s and remember. This forum is likely the most authoritative source of info on the Honda fours.

[Barney1982]

Sorry to jump on to an old thread.
I was wondering about leaving my lower crankcase unpainted as per original.
If I was to get it vapour blasted, would I need to clear coat it or something to stop it corroding?

[HondaMan]

Sorry to jump on to an old thread.
I was wondering about leaving my lower crankcase unpainted as per original.
If I was to get it vapour blasted, would I need to clear coat it or something to stop it corroding?

No: the vapor blasting seals the surface by annealing the aluminum-zinc metals. However, if you are going to paint, you need to let the vapor-blaster know: they treat them differently for "to be painted" versus "run bare" versions. And, these both look a little different when you get them back, with the "to be painted" versions looking more dull than the other version.

[jlh3rd]

So just to clarify this, the top crankcase was silver paint but the rest was just bare aluminium? Where would one go to find this kind of specific information?

thanks for your help! (also thanks to everyone else too!)

i have done extensive research on vintage honda painting, especially for my unrestored 550F. I have never come across any official, honda literature that states how honda finished their engines. Never. So, that leaves it to internet opinions and beliefs.
     Or someone who has an original, unrestored bike, which I do.
     I'm in the top engine and cases painted from factory crowd. I can send pics that show areas of paint flaking. I do not think any clearcoat was used....i repeat, think...
     Clutch covers, alternator covers, drive sprocket cover were a polished , but not too polished, aluminum with a proprietary clearcoat from honda which no one has the formula for or which you could ever get from honda....so, you have to get and decide whose opinion as to the best substitute you want to use.....or.....leave them uncoated and keep them polished....(note) most people over polish these pieces, they were not shiny....
      I'll be happy to send pics of those also.....
hope this helps.....