what have you done to your "bike" today

[VTR Phoenix]

If that's happened was the black paint an oil or water based paint?

More likely the cold damp weather and applying too much too quick. Fuel resistant lacquer is the worst for this and causing a reaction.

Stick the can in some hot water to warm it up a bit first and start with very light dust coats, leave for 10-15mins between coats building the amount applied each time. Only on the final coat do you give it a good heavy coating but not so heavy that it runs. Just enough so it covers well and leaves a good finish.

So why has it reacted to only the black and not the silver then? If the paint and lacquer aren't compatible then they will react like that. Same if you haven't used panel wipe after handling then the natural grease from your hands on the panels will cause the same reaction

[AMCQ46]

I might have just bought another bike



little 160cc supermoto minibike to race

Wicked. I didn't realise you were racing it with slicks. No wonder you said it was a great laugh

3 sets of wheels.... slicks, wets and inters and everybody uses tyre warmers so you can go for it from the first corner!
Also fitted with close ratio gearbox, lightened flywheel, brembo front caliper, custom under slung pipe. shock and forks have compression and rebound adjustment, ......... its got better spec than the firestorm! .... and just about as noisy!

[fabiostar]

Fitted a new EBC heavy duty clutch kit to the new lady and waiting on water pump seals to get the engine buttoned up again.

[redpig]

If that's happened was the black paint an oil or water based paint?

More likely the cold damp weather and applying too much too quick. Fuel resistant lacquer is the worst for this and causing a reaction.

Stick the can in some hot water to warm it up a bit first and start with very light dust coats, leave for 10-15mins between coats building the amount applied each time. Only on the final coat do you give it a good heavy coating but not so heavy that it runs. Just enough so it covers well and leaves a good finish.

Yes thats the way, very light coats, letting it dry in between.

[AMCQ46]

lacquer didn't run, its just turned the black painted sections to crinkle finish after the first dust coat! adding more coats just made it worse.

I will look at it later, and decide if I start again or use it for a year.

[TheGingerBeardMan]

I will look at it later, and decide if I start again or use it for a year.

Start again. Can of paint stripper, remove the lot, and do the black tops with the gold bottoms. Well, everythings off the bike at the moment so why the heckers not??

Why rub down the laquer and respray if the chance of the same happening? Hmmm. Nah...strip back to bare aluminium...etch primer....degrease with methylated spiriits or acetone (NOT degreaser or carb/brake cleaner, as that leaves a tiny film), then tins of paint that are the same make/brand. A clear satin laquer will not make it too glossy.

That said, I have used primer, paint and top coat all the same brand, and I did a reasonable job and all looked well....until, like you, the top coat was applied and it all turned to sh1t. A pro paint sprayer suggested that the primer was possibly OK, but the basecoat was applied with too low a surface temperature, thus not bonding the paint chemicals properly to the primer (which is why a paint booth is always toasty warm).

When you apply the laquer on top afterwards, the chemicals lift the actual point from the forks, as it's not adhered properly - hence the crinkle finish.

So, etch primer is always ok. Degrease, and then before painting a colour, use a hair-drier to get the fork leg toasty warm (not mega hot, as the paint can dry patchy too quick)

The same applies after leaving the painted fork somewhere warm to cure (airing cupboard). Before applying laquer, warm up the fork leg again with the hair drier.

Best of luck.

[VTR Phoenix]

I still maintain incompatible paint and lacquer!

[AMCQ46]

I did use a hot air gun before & during most of the painting steps, but I admit I didn't use it before last nights lacquer.

I am not a "completer finisher" detail type mentality, I am more a 70/30........ so I hate doing things a second time.... if the finish doesn't flake off when I rub it, it may still be on the bike next time you see it.

[AMCQ46]

If that's happened was the black paint an oil or water based paint?

I will have a look at the black paint can, as it must be some difference between it and the silver, although the black only had 2 days to cure, the silver is over a week since painted. perhaps too cold to cure quickly, although I have a small radiator sitting under them all the time???????????

[VTR Phoenix]

2 days is plenty especially if they are above a heat source. I have sprayed primer and basecoat one day and lacquer the next. All were 2pak paint.

Your black paint wasn't a high temp or gloss paint was it?

I am assuming the leg was keyed then primer, then keyed then silver, then the part to be black was keyed again then sprayed black? This will ensure the paint sticks before the lacquer is sprayed.

Not trying to teach to suck eggs but been there done that and have had to take right back to plastic before. I have also had it over filler where that hasn't dried completely and then the oils escape and cause the exact same results.

[AMCQ46]

2 days is plenty especially if they are above a heat source. I have sprayed primer and basecoat one day and lacquer the next. All were 2pak paint.

Your black paint wasn't a high temp or gloss paint was it?

I am assuming the leg was keyed then primer, then keyed then silver, then the part to be black was keyed again then sprayed black? This will ensure the paint sticks before the lacquer is sprayed.

Not trying to teach to suck eggs but been there done that and have had to take right back to plastic before. I have also had it over filler where that hasn't dried completely and then the oils escape and cause the exact same results.

might be the problem.... sanded down, cleaned with Tric, etch primer, then didn't do any sanding to key after that..... paying the price for being lazy now

[Wicky]

Etch primer (toxic stuff! and ideally needs air fed respirator when applying) is hygroscopic and needs overcoating soon after application. If left a day or two then goodness knows how much moisture from the air it will suck up.

Not the best time of year for paint spraying in sheds. Did it one Winter and it was nightmare, even after trying to wam up things in the house then whipping them in the shed to paint, condenstaion was a problem when spraying on two pack.

Home spraying, unless for smalll items best left till the Spring when things warm up.

[agentpineapple]

i've been spraying a friends front wheel in temps between zero and 5 degree's, i've been warming the wheel up indoors, then spraying outside, then bringing it indoor to dry. plus i don't have any eych primer, some i'm putting down a coat of black metal paint, similar to hammerite, then going over it with a couple of coats of gloss black. fingers vrossed it works ok....
the base coat of black metal paint has gone on really well, it's a matte black and actually looks rather good. but it's now too late, as i've applied the first coat of gloss black, i'll have to wait until the morning to see how it drys.

[VTR Phoenix]

You don't need to use an etch primer, there is much confusion about it. It is not used to stop corrosion it does exactly what it says on the tin. It is for use on new metals that have not previously been etched i.e. sanded, sandblasted etc. If you sand back to bare aluminium or steel then you should use the relevant primer to seal it. There are aluminium primers. They can then be left as long as you like before basecoat is sprayed. Primers usually are good to paint over within 20 minutes. 5-10 minutes between primer coats. 2pak paints dry a lot quicker as their drying time is mainly down to the solvents evaporating. You can get fast or slow drying lacquers. I prefer the fast drying which is usually touch dry within the hour at about 15c

[bigtwinthing]

Just took delivery of the Ohlins Fork internals and Springs and the Rear shock oh Joy. Bike Porn to me.