Z1-R Engine Repaint

Had a very disappointing result from the engine repaint!!!!
I spent a lot of time working the engine externals with wet/dry sandpaper and brass brushes
to get a surface for the new paint to key into. Gave it a good wash down and allowed to dry.
Masked it up and waited for a nice sunny day to take it outside.
I had agonised over which paint to use and thought I was clever to choose POR-15 chassis topcoat
as it's a satin black with very good durability, chemical resistance, and weathering properties.
It's also supposed to fine for Direct to Metal (DTM) so I though "Ok, this is the one!"
Anyway, loaded up the spray gun with suitably thinned paint (POR-15 is quite heavy) and away we went.
Initially looked ok ,then as I progressed the paint finish began to go all krinkly with lumps forming in various places! -too late to stop!
Some areas look fine but others are crap - see pic.

Wow...that sucks. I heard of a lot of people using that paint without problems.
What kind of soap did u use....I always use Dawn dish soap.

Looks like I'll have to get the wet/dry out again and prepare the surfaces- this time Ill be using rattlepacks,
probably VHT satin engine enamel (my initial choice - wish I'd stuck with it!!!!! )

Another pic to show the lumpy/mottley finish, right next to some not so.
(I suspect that a PO has painted the engine with different types of paint, some of which is incompatible with the paint I used. )

Yep, just used a mild dishwashing soap solution - so that should've been ok.

I rubbed back the crappy finish on the clutch cover and applied some of the VHT satin enamel (primer first) over the POR-15.
This came out ok , so will be the way I'll go.

More pics to come after I get the thing prepped - again!! Then painted - again!!

Man, why did you not do the research here? POR-15 is for rust control, frames and chassis'.
PJ1, VHT, or Plasti-cote rattle cans. Is what you should have used! All Work Great! What did you thin the POR with? Did you use a cheap spray gun from Chinese harbor? You need real chemicals for thinning, real lacquer thinner, urethane grade reducer, base maker.
Sounds like people thinning rustoleum with mineral spirits, and spraying it????
Looks like you got a lot of work to do over?

Thought I'd done my homework, but guess not - given the results!!!!
Oh well, I'm not frightened of sharing my failures - hope others can learn from my "experience"
For info -
I thinned the POR with its own POR thinners to get correct consistency for spraying.
Spray Equipment (not el cheapo variety) was cleaned out with POR thinners first before spraying.
Did a test spray on a similar surface and looked to be ok - still think it is a paint incompatibility issue.
In any case it's history now and I "look forward" to another few hours of prep work!
It's winter downunder so plenty to keep me busy in the shed!

Maybe too late, but Otkar seemed to have good experience with Guncoat products.

www.kzrider.com/forum/6-paint-a-bodywork...gun-kote-1200#263808

I remember another build by a guy who used a lot of gold Guncoat. It would be interesting to find out how well it has held up for them.

I used PJ1 on mine and it came up lovely. Though it hasnt been on the road yet so I can comment on its durability.Fingers crossed itll be good,I dont envy you having to redo it.

You reckon the bad patches are possibly a reaction with the paint underneath.Be sure the new paint isnt going to react badly with the Por !!

Good luck with it.

It is usually a bad idea to paint over someone elses repaint. Always good to do a small test area first to see what happens.

weales wrote: (I suspect that a PO has painted the engine with different types of paint, some of which is incompatible with the paint I used. ]

Bingo. Always strip to bare metal. Seen that many times. When acrylic enamel first came out in the 70's, that stuff would lift ANYTHING.... including itself! You had to spray it all on quickly. If you tried to come back over it after it had dried it would wrinkle.

I've used Chassis Coat before and it's not friendly to spraying. It's killer thick and even after thinning it doesn't flow out very well. It looks like the areas where the paint was sprayed straight on are okay, but the overspray started to accumulate on all the adjacent surfaces and build up in a massive layer after layer of orange peel. Sorry for the problems, but I just don't think that's the proper paint for an engine.

Thanks to all for feedback - the message is clear, although the paint is not....!

On a more positive note, as a test I painted over an area of the POR with VHT satin finish engine enamel -
after rubbing it back just enough to smooth off the crap wrinkly finish and to provide a key
The end result looks good and I'll post some pics soon.