5 replies to this topic

[mk=john]

Hi
I am in the process of painting my Mk1 mini. On the underside, there are several areas where the cellulose filler primer has cracked, and these seem to only be in areas where there are tight bends, and where there are 90 degree panel joints e.g, boot floor to heel board.

Why would this be happenning? i was really careful with my prep and just a bit annoyed this is happenning. is this a common problem when using celly filler primers paints?

Whats the best way to correct this?

Thanks
John

Edited by mk=john, 02 October 2009 - 11:59 AM.

[mk=john]

Hi
I am in the process of painting my Mk1 mini. On the underside, there are several areas where the cellulose filler primer has cracked, and these seem to only be in areas where there are tight bends, and where there are 90 degree panel joints e.g, boot floor to heel board.

Why would this be happenning? i was really careful with my prep and just a bit annoyed this is happenning. is this a common problem when using celly filler primers paints?

Whats the best way to correct this?

Thanks
John

Anyone, please?!

[Paul Wiginton]

Probably the paint was applied too heavy and not dry enough between coats so its cracked as its dried

Paul

[cooper_shaz]

Can you put up pictures of this??

As mentioned above, it sounds like the paint was applied too heavy. The reason this happens is that with heavy paint, the surface dries and forms a film, as the paint underneath dries the solvents evapourate and the paint shrinks, this causes the cracks to appear.

It could also be a reaction between the cellulouse and the coatings underneath. To avoid this you paint a barrier paint over the surface such as "Barcoat", you spray this straight out of the tin and do not thin or sand it when painted. It is the thinners in the Cleeulouse that react with the other paints.

Cheers
Shaz

[Big Guns]

Can you put up pictures of this??

As mentioned above, it sounds like the paint was applied too heavy. The reason this happens is that with heavy paint, the surface dries and forms a film, as the paint underneath dries the solvents evapourate and the paint shrinks, this causes the cracks to appear.

It could also be a reaction between the cellulouse and the coatings underneath. To avoid this you paint a barrier paint over the surface such as "Barcoat", you spray this straight out of the tin and do not thin or sand it when painted. It is the thinners in the Cleeulouse that react with the other paints.

Cheers
Shaz

I can only ask "did you force dry it using heat"? It really does sound like rapid drying were shrinkage occurs. Naturally the paint cracks at it's weakest points...ie: tight angles.
Cheers.......Dave

[mk=john]

Can you put up pictures of this??

As mentioned above, it sounds like the paint was applied too heavy. The reason this happens is that with heavy paint, the surface dries and forms a film, as the paint underneath dries the solvents evapourate and the paint shrinks, this causes the cracks to appear.

It could also be a reaction between the cellulouse and the coatings underneath. To avoid this you paint a barrier paint over the surface such as "Barcoat", you spray this straight out of the tin and do not thin or sand it when painted. It is the thinners in the Cleeulouse that react with the other paints.

Cheers
Shaz

I can only ask "did you force dry it using heat"? It really does sound like rapid drying were shrinkage occurs. Naturally the paint cracks at it's weakest points...ie: tight angles.
Cheers.......Dave

Hi
The cracks are only on areas of the underside. i have already scraped off the cracked bit, and brished on primer and top coat onto those areas. Its in no way visible, When i apply top coat to the exterior, i will be much more careful obviously! I didnt speed dry the paint at all, but I did it in my garae when the temp was aprox 20-23 degrees celcius outside