Dash 2 pack cracking

[Graham]

Seasons Greetings to you all, just gathering all the car parts from the various hiding places I stashed them away as I refurbed them during BOU's strip down and horror of horror my beautifully (if I say so myself !) re veneered dashboard now has multiple cracks in the 2 pack lacquer. I spent ages re veneering and polishing it and now its not fit for firewood

 

So will I have to strip all the 2 pack of the veneer and start again or is there a way it can be 'fixed' ?

 

What did I do wrong in applying the 2 pack to make it crack ?

 

A Merry Christmas to you all

 

Graham

Edited December 24, 2016 by Graham

[foster461]

Where was it stored Graham ?. Wood expands and contracts with changes in temperature and humidity so if the base wood or veneer moved, that would crack the clear finish. It may not be a problem with the clear at all.

 

Stan

[Don H.]

A crosslinked polymer (2-pack) will lose some volume as it cures. This can create internal stresses as the shrinkage gets locked in. Unfilled systems are more sensitive than filled systems, like paints. Normally, they've thought about this and it's managed with no issues. But if the formulation is over-cured, as in adding too much hardener, things like this can happen. More hardener doesn't make a better film.

 

I like Stan's expansion/contraction hypothesis better, though, and I'd bet you were careful about 2-pack mix ratios.

[RogerH]

Hi Graham,

it sounds like the lacquer was too brittle and Stan's idea happened.

 

They will all crack eventually - mine lasted about 14 years.

 

What two pack lacquer did you use.

Rustins is good but if too brittle it will crack.

 

Perhaps a quality single pack varnish may be better for DIY use.

 

Roger

[jean]

A varnish for wooden floors, available in gloss, satin etc..... fully safe against scratches