Paint. cracking effect ?

[njkmr]

Ok ,hope you can answer this for me please .
Sanded down skirting and window board in bedroom prior to redecorating /papering room .
After sanding down the wood (previously been glossed 15 years or so ago probably )I applied two coats of undercoat /primer .Sanded again ready for glossing .
Apllied the gloss and got a strange finish ,which looks like lots of little pools within the paint .Thought I would give it another coat which may get rid of the imperfections .Started to look OK ,then as it dried a bit it started cracking /creasing up .But only at one end of the windowboard and a small section of the skirting on the other side of the room .
Now I have been cleaning brush in whitespirit,then washing up liquid to clean off the white spirit in between coats .Rinsing with lots of water .
I have also used the same brush to paint matt ceiling paint on the plaster coving in between glossing and washing brush in water only.
Can anybody explain whats going wrong .?
I will have to sand down again ,but I dont want to turn this job into the Forth Bridge of painting jobs .!!
Many Thanks for your help .
Regards
Rob.

 

[joe-90]

Sounds like you are using a wet brush for gloss. Make sure your brushes are DRY when you use OIL based paints.

 

[njkmr]

Thanks for the reply joe-90 .
Yes the brush may well of been wet ,or damp anyway .
I did shake off as much water as possible so it wasnt dripping .Would a damp brush cause this with liquid gloss .?
Regards
Rob.

Having said that the cracking occured at the far end of the windowboard and I started at the other end first,so would there still be water present on the brush do you think .?

 

[joe-90]

the water gets in the metal case that holds the bristles in (ferrule). As you paint it works its way out and down the bristles. Try using two seperate brushes - keeping your gloss brush in a tin of white spirit.

 

[njkmr]

Yes will do joe-90 .
Thanks again .
Rob.

 

[njkmr]

Spoke to someone today who said it may be because I tried to do a second coat of gloss before the first coat of gloss had dried properly .
As Im impatient this could be true .
Anybody else confirm this may be the problem ?
Regards
Rob.

 

[Growler]

Spoke to someone today who said it may be because I tried to do a second coat of gloss before the first coat of gloss had dried properly .
As Im impatient this could be true .
Anybody else confirm this may be the problem ?
Regards
Rob.

This often happens, however you did say... Apllied the gloss and got a strange finish ,which looks like lots of little pools within the paint .Thought I would give it another coat which may get rid of the imperfections ... so the first coat had already gone funny on you.
Can't see why you've gone completely "over the top" and put 4 coats on, or even 2 undercoats.
If your undercoat wasn't fully dry when you first applied the gloss, then this could be your prob or.. it may have been some silicone/ polish, Mr Sheen /Pledge lying on the wood which you haven't been able to wash off. Polish, doesn't usually show up with the undercoat and then when you gloss it.....it "pools", to use your term.

So initially, it could be silicone/polish,which formed "pools", then followed by another gloss coat, too early, which cracked it.

Did you give it a good washing down with sugar soap? to de-grease, especially as it hasn't been painted in 15 years.

 

[njkmr]

Growler thanks for reply.
No i didnt clean it off after sanding !!!
I presumed sanding would take off all the grime .
I will know for next time .

I applied all the coats because I wanted a nice flat finish with no imperfections ,so I sanded in between coats to get it as flat as I could .

I guess you live and learn .
Certainly picked up a few tips for next time .
Thanks Again .

 

[Zampa]

Out of interest..and a bit of a long shot..but was the paint water based?...I saw this happen in the week, a trainee was brushing n a water based coating using a brush that had been washed out in white spirit and not washed again in detergent and water...this causes cissing/cessing..which sounds like what you are describing.

It might also be wax or polish on the surface before you painted it.

 

[njkmr]

No I think the paint i put on was oil based .Colours from B and * .
Regards
Rob.

 

[Zampa]

Hmm probably down to contamination of the surface then..silicone based polish