Topic: how do I know if I still have clearcoat on?

[crashmaster]

I've been cleaning up some of the discoloring/tarnish on my 72 CB750 restoration. I've been using WD-40 with steel wool, some Dawn detergent. I know it's alot of work and elbow grease, but not making a ton of progress. I do not want it all shiny chrome looking, though. Just get the tarnish off so it looks like back in the day is what I am after. But how do I know if I am fighting clearcoat, or do you automatically strip the parts first regardless? Seems like stripper could get messy on an engine still in situ. Thanks.

[jonda500]

rub it with cutting compound or metal polish on a white rag - if you are rubbing aluminium the rag will go dark almost black, where as clear coat will only slightly soil the rag. Silver engine paint will show as dark silver color on the rag.
John 

[crashmaster]

Thanks John! I was gonna try something like this on a cordless drill:
https://www.menards.com/main/tools/power-tool-accessories/abrasive-wheels/tool-shop-reg-aluminum-buffing-polishing-set-14-piece/apk-1/p-1444421184844-c-10154.htm

[piefairy]

Be careful when using drill powered stuff. It will cut fast through any coating. I would hand polish a spot until you see exactly how much it needs, then proceed carefully with the drill.

[crashmaster]

OK - thanks piefairy. Will do (great name btw 
When you say cut through any coating - what "coating" do you mean?

[Ozzybud]

If you truly want it to look like it did back in the day you will need to likely remove the  pieces then strip the clearcoat, progressively sand to remove blemishes and corrosion, finishing up with at least 2000 grit. Then satin polish. Never to a mirror finish. Then apply a 2k clearcoat to protect from future oxidization . If you have black marks, sqiggles and streaks that is corrosion. Where moisture got under and broke thru the clear.

The first 3 pics below are a unrestored 500 Mile original CB750K. That is what they looked like when new.
The last Pic is my CB550K clutch cover where I attempted to make it look as original as possible.
I have a detailed procedure id be happy to share.

[crashmaster]

Ozzy - thanks for the pics. Great reference

[piefairy]

OK - thanks piefairy. Will do (great name btw 
When you say cut through any coating - what "coating" do you mean?

I misread your original post. I was referring to clearcoat, but it sounds like you are trying to remove it. I agree with Ozzy, pull the part and strip the clearcoat, sand and polish. One product I have used with good success is Mother's Mag/Chrome polish. I used it a lot on brushed stainless and chrome parts, works wonders. Try it by hand on a spot and if it looks good, use a powerball drill attachment and carry on. Its such a fine grit paste I don't worry about it cutting or burning anything. It will not strip the clearcoat, so you will still need to strip it off first. It may make it shiny-er than you want it. Heavy duty polishing compound may give you a closer result to what your after.

[MauiK3]

Most original clear coat is pretty aged by now and should be easy to see.

[Bodi]

Yes you can polish the alloy but bare metal will inevitably tarnish. I haven't found a clear coat paint that holds up to engine heat well.
I have used a product called GunKote. It produces a very thin hard surface finish. I use black but it does come in a clear version as well as other colours.
It is kinda expensive, needs a spray gun, and has to be oven cured. Send the wife out for a spa day and get the house aired out before she's back.
Covers I did 20+ years ago still look good, spots with a lot of wear ie beside the shift lever are slightly lightened but it has held up amazingly well.

[CycleRanger]

I used spray brake cleaner to remove the remnants of the clear coat from the covers on my engine.
Then I polished everything. Polishing sucks.
A couple of times a year I hit the covers with some aluminum polish.

[Ozzybud]

I use PPG Omni catalyzed clear on hubs ,forks and engine cases.
It stands up for years and does not yellow. The engine heat does not affect it.

[M 750K6]

Initially I went over mine with a polishing mop on a drill and chrome / Al Polish, to get everything nice. I now hand Polish every 6 months (forks as well. Takes 15 minutes and is an opportunity to give the bike a close inspection (frame etc.). Always looks good. Not mirror perfect finish, just fresh and shiny. I quite enjoy that 15 minutes though.

[MauiK3]

Ozzy, what do you spray it with?

[Ozzybud]

Ozzy, what do you spray it with?

A baby HVLP gun.  $30.00 on Amazon