Watching paint dry!

[Gern]

Hi folks. Can somebody help please?

I used some Humbrol matt enamel thinned with white spirit to spray a kit. That was three days ago and the paint still feels tacky! Is it possible the paint has deteriorated in some way as the tin looks quite old?

I've done several sessions since then using other Humbrol and Revell enamels and they've all dried and allowed me to mask and paint with no problems so I don't think it's my technique.

Everything has been primed beforehand using Halfords grey or white primer so I don't think there's a problem with any sort of grease/oil on the plastic.

If it doesn't dry properly, how can I strip the paint so I can start again?

Gern

 

[tecdes]

If it is still tacky Dave white spirit with luck will remove it.

I use acrylics & have found white the very devil taking longer than other colours to dry & also coverage is not as good.

I am a sceptic & always use the primer of the finishing coat manufacturer then you have a least discarded one avenue if all goes wrong. Had problems when I first started with Humbrol & non Humbrol primers.

Laurie

 

[stona]

Hi folks. Can somebody help please?I used some Humbrol matt enamel thinned with white spirit to spray a kit. That was three days ago and the paint still feels tacky! Is it possible the paint has deteriorated in some way as the tin looks quite old?

Gern

It may have deteriorated but Humbrol had some serious quality control issues a while back and you may have got a tinlet from one of those batches. It should have dried in three days,generally 8-12 hours is plenty.

I'm confident that this has nothing to do with your technique.

You've got two choices really. You can sit tight and hope that it will eventually dry though if it is a bad batch it may not. Second option is to remove the paint. You didn't say what you have sprayed it on so I don't know how accessible the sprayed area is.I would start with White Spirit or similar( Turps or a substitute). If it hasn't dried it may very well wipe off. I've resorted to an old tooth brush,cotton buds,rolled up kitchen roll and all sorts plus solvent on occasion!

There's a good chance your primer will stay in place. The Halfords Plastic Primer sticks like you know what to a blanket!

I would not use anything too "hot" like cellulose thinners as you run a significant risk of etching the plastic and ruining the kit which,at the moment,should be salvageable.

Good luck and keep us posted.

Cheers

Steve

 

[backonthecase]

I'd wager it's either a bad batch or it's not been mixed correctly... Humbrol gloss is a b1tch to get right but the matt, if mixed correctly, should be fine...

HTH

Stuart

 

[madsarmy]

I would say it's a case of the paint not being stirred enough. I used to have the same problem until I made a paint stirrer out of piano wire for my pillar drill. A couple of minutes stirring & I have not had the problem since.

Here are the two designs I found worked best.

View attachment 50469

View attachment 53152

 

[tecdes]

Certain you are right Madsarmy.

The body is left at the bottom & the driers rise to the top. If you use the paint without decent stirring then you use up the driers on top & when trying to use further down the driers are depleted & will cause longer drying times sometimes if at all. If it is an old paint then the probability is that the driers will have really separated.

Laurie

 

[Gern]

Thanks guys.

Gern