Baldini Posted October 1, 2004 Posted October 1, 2004 I've heard two theories as to why black wrinkle finish bubbles. Both, to me, are plausible. During manufacture moisture is trapped between layers of paint which expands on heating causing outer layer to bubble. Bikes used esp in town/traffic & not benefiting from cooling airflow are getting hot, then being put straight into garages/sheds whilst still hot = baking paint. With regard to the second theory, it would suggest to me that time on a Dyno would kill the paint for sure if it's caused by overheating? Any comments/experience? I am lucky w/paint so far at 10Kmiles. I am thinking of doing some mods which will mean bike will need dyno time... KB
Guest wier Posted October 1, 2004 Posted October 1, 2004 My Scura has around 4000 miles on it varying from town riding and motorway work, my paint started bubbling around of 2000 miles. I've heard two theories as to why black wrinkle finish bubbles. Both, to me, are plausible. During manufacture moisture is trapped between layers of paint which expands on heating causing outer layer to bubble. Bikes used esp in town/traffic & not benefiting from cooling airflow are getting hot, then being put straight into garages/sheds whilst still hot = baking paint. With regard to the second theory, it would suggest to me that time on a Dyno would kill the paint for sure if it's caused by overheating? Any comments/experience? I am lucky w/paint so far at 10Kmiles. I am thinking of doing some mods which will mean bike will need dyno time... KB 34593[/snapback]
Admin Jaap Posted October 1, 2004 Posted October 1, 2004 With regard to the second theory, it would suggest to me that time on a Dyno would kill the paint for sure if it's caused by overheating? Any comments/experience? I am lucky w/paint so far at 10Kmiles. I am thinking of doing some mods which will mean bike will need dyno time... Let's just say the dynorun I did, didn't do any good to the engine paint... But mine was already blistered
Ballacraine Posted October 2, 2004 Posted October 2, 2004 Well, although I am not a paint sprayer I know a few folk who are. As I understand it, the secret of a good job is down to the preparation. You have to have a good clean, surface to key on for starters. Thin coats are reckoned to be a lot better than one thick coat. The drying & curing process works better with thin coats. My guess as to why there are problems with this finish? I would say it is a combination of factors. The fundamental cause I think, is that that the paint was not applied in the above fashion, but the coating was probably too thick for the application anyway. Heat dispersal works better through thinner, properly cured layers. Anybody any other opinions? Incidentally, touch wood, my wrinkle finish is holding up well....and the Guzzi's too Nige.
Baldini Posted October 3, 2004 Author Posted October 3, 2004 ...The fundamental cause I think, is that that the paint was not applied in the above fashion, but the coating was probably too thick for the application anyway. ...Incidentally, touch wood, my wrinkle finish is holding up well.... so why are some bikes OK while others bubble? Different @ manufacture or different lives? KB
Guest Jeff Kelland Posted October 3, 2004 Posted October 3, 2004 When the paint on my engine bubbled off, a coat of semigloss black paint could clearly be seen under the wrinkle paint. At the time, others with the same problem noted the same thing. Either that semigloss was an undercoat that the top coat didn't adhere to or it was an incorrectly applied topcoat that the painters covered up on the cheap.
Ballacraine Posted October 3, 2004 Posted October 3, 2004 so why are some bikes OK while others bubble? Different @ manufacture or different lives? KB 34685[/snapback] Obviously usage is a consideration, but I suspect the prime cause is the paint is really too thick for the application anyway. If you are after a more durable coating several thin coats of a decent VHT matt or satin paint properly applied & cured is your best bet. That is what I shall be doing when mine calls enough. Nige.
Baldini Posted October 3, 2004 Author Posted October 3, 2004 ...several thin coats of a decent VHT matt or satin paint properly applied & cured is your best bet. That is what I shall be doing when mine calls enough. I've never understood why the cases are painted anyhow. If the paint on mine does go I'll take it back to metal. What happened with speed limits on the Island? I used to come over for the Manx - never forget those times - something very special, but I can see why things would change. KB
Ballacraine Posted October 3, 2004 Posted October 3, 2004 If it actually stays on, paint is easier to maintain. I used to get fed up polishing around the webbing so I satin blacked the cases on my 750-S3. It looked smart & it stayed on! Nothing yet. Just slowly encroaching speedlimits. It is still under consideration! Nige.
Baldini Posted October 4, 2004 Author Posted October 4, 2004 ...I used to get fed up polishing around the webbing... I miss getting the solvol out... best bit's the finning by the front mount bolt & them bits tucked up behind the top of the timing cover... KB
Ballacraine Posted October 4, 2004 Posted October 4, 2004 I miss getting the solvol out... 34722[/snapback] Many, many years ago, I had a near religious experience! I was polishing back a top coat on a petrol tank & a blob of rubbing compound fell onto the rockerbox of the engine stored under the bench. I wiped it off... Instant gleam! Much cheaper than Solvol & the same or better results with less elbow grease. I have used it ever since. It is superb on a decent untreated alloy. Nige.
tikkanen Posted October 4, 2004 Posted October 4, 2004 As I understand it, the secret of a good job is down to the preparation. You have to have a good clean, surface to key on for starters. Thin coats are reckoned to be a lot better than one thick coat. The drying & curing process works better with thin coats. Yep Nige, preparation is the key word. As we used to say in the Army: "Preparation and Planning Prevents a Piss Poor Performance" and you can't argue that. My Scura looks like a bull frog with warts so it's warranty time again, unfortunately. I'm having it done here during winter - I expect to hang up the wheels in a month or so depending on whether the night temperatures will drop below zero. Søren
Fazernick Posted November 12, 2004 Posted November 12, 2004 The paint may contract-expand at a different rate from the base metal. Perhaps the most damage is done when rainwater falls on the hot engine which causes the paint to contract faster than the metal with resulting separation. My Centauro's paint (Silvery-gray and smooth) had adheared well on the engine through 28.000 km's. It isn't rocket science just good preparation and proper coatings. I just can't imagine why the factory won't improve on the paint and instead pay a whole lot of money on warranty claims. Nick
Admin Jaap Posted November 12, 2004 Posted November 12, 2004 Nick, AFAIK the bad paint only was used on 2002 and beginning of 2003 models. The glossy paint they used after that seems to be ok.
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now