i sprayed mine recently and deliberately didn't use Hammerite on the advice of the guy at Halfords... despite it being a brand name and pretty decent stuff he said, and i sorta quote, it's a pain in the arse when straight on metal or smoothed surfaces, i.e. brakes, strut brace etc etc :? so just went for some high temp gloss spray instead, pretty sure it was halfords own brand too. looks friggin ace imo to be honest - it doesn't make any sense why it'd still be wet if you've managed it before on mini's, since it's not a huuuuge job to do i'd say start over

 

One of the fronts has developed an ever slight wrinkle effect localiesed to where i just touched up the scratch.

I think Smoothrite paint needs to be touched up within 6 hours or else you have to wait for 6 weeks before it's re-coated. This could be why you have slight wrinkling local to the area touched up.

With regard to the paint still being soft what was the weather like when you were painting? If it was damp or humid it may be responsible for the slow drying.

You could try speeding up the drying/curing with a halogen lamp or something similar if available.

Sorry I can't help further.

Alan W

 

HI,
It may not be a huge job - it is however a really time consuming one when you have to strip all the brakes, then reapply-and it has to be doen to each wheel individually due to work space and a sloping driveway!

It was pretty warm when i applied- but certainlty for the last two days its been going from sunny spells to showers.

I havent got anything like a halogen lamp-

any advice on taking it for a spin everycouple of hours to heat up the calipers and dry from inside out?

 

Japlac...japlac....japlac. :roll:

 

Most likely you haven't cleaned the surface as thoroughly as you thought, and the paint hasn't been able to key to the caliper - it shrinks as it dries and loses volume, and whereas normally it would relieve the drying stress by thinning out, it has taken the route of least resistance and pulled away from the substrate instead. Waterborne paints are fine in exterior applications provided you do thorough surface prep and preferably apply a suitable primer (regardless of what the can or the bloke in B&Q says) first. I know, I work for them.
Loads of people use Japlac which seems to be a good hassle-free route.

 

The short answer is that Hammerite paint was refomulated a year or two ago and is now,IMHO,POOR.
It used to be quick drying with good coverage and you could recoat in 30 mins,now it's streaky to use and takes ages to dry.
I think it's because it's gone from solvent based to water based...a good product ruined 'to save the environment' I suppose.

 

Cheers - ok advice taken on why its being a pain in the rear when it comes to drying.

Any advice on how to get it to dry?

Will it never dry?

(im not repainting them - if i strip them back thats it as is too time consumming to redo all of them wheel by wheel)
Will taking it for little trips dry it up.

im due to do a 200 mile trip tom, followed by a 200 return journey the next day - is it safe if the paint is not dry?

many thanks

Mod

 

Most of the Hammerite range went to water based years ago, well ahead of the VOC 2007 regulations coming into force (along with a load of other metal paints). The ones that haven't will do so before VOC 2010 comes into force so we'd better get used to water based! I can't speak for the competitors but Hammerite uses styrene technology which gives extremely good water resistance when dry. Wall paints seep into the plaster and form a mechanical key into the pores of the substrate, but this can't happen with metals (no pores) so the adhesion problem needs another solution. Most metal paints are "adhesion promoted" so they chemically bind to the substrate, but if the substrate i.e. the caliper is not clean and completely free from grease, the binder will not see the metal and you have no bond. Water based paint technology is constantly improving and does not necessarily mean rubbish - but surface preparation becomes more important for a good finish.
The paint companies do the best job they can - within the bounds of legislation and costs - to sell a product at a sensible price with a good profit - you might stamp your feet and shout "not fair" at losing solvent borne but it is the way things are going in most of the market and there is nothing to do but get used to it! :wink:

re. drying - I would seriously remove and start over when you get the chance - even when it dries properly you have what sounds like a terrible finish and not what you hoped for. The only risk to driving as is is the wet paint contacting the disc and reducing braking efficiency - and leaving nasty red streaks until you've burned it off.

 

Just a side note Hammerite's has a 2 year shelf life. Should last longer but if kept v.hot or v.cold can degrade quickly.
Also most of their products only good to 80 Deg C (150 Deg C for short periods whatever short is... :?: )
I'd say for calipers you need a better temperature product. 8)
Oh and Halfrauds were selling a German caliper paint kit for a fiver in their sale items few weeks ago (Eastleigh, Southampton, Basildon and Slough branches anyway.. man I get around)

 

I did mine with hammerite the other week. did you wipe the caliper with thinners first? that's a good start. Anyway shouldn't matter. I scratched mine putting the clip back on too but just touched it up afterwards and leave it. If you have done several coats chances are it is dry to touch but will need longer to harden off. Don't worry about it, it with harden eventually!