Bubbles causing me panic. Help please

[Jupiter01]

I am applying a top coat to my MDF bookcase. This has had 2 coats of MDF primer.


I have a Valspar Satin mixed colour for my top coat. When I apply this with a foam roller (exact approach I used for 2 coats of the primer), I am getting lots of small bubbles.



Applying with brush doesn’t cause this issue.


I don’t want to go any further until I know what’s going on.

Can you please advise as I am now downing tools

 

[just pumps]

Bubbles causing you to panic, really? Just use a brush then.

 

[Jupiter01]

Can someone advise on this please? I am reluctant to brush as it will take long and compromise the finish.

 

[opps]

The foam roller is the cause of the problem. As you roll it over the surface it "injects" bubbles in to the paint. If you were painting coloured water the bubbles would burst instantly and not be noticeable.

I seldom ever use foam rollers. Buy a "mohair" type rad roller sleeve.

https://decoratingsundries.co.uk/roller-sleeves/sim-velour-mohair-mini-roller-refill-4-inch

Alternatively, wait a few moments after rolling and then (without reloading the roller) gently roll it back over the surface in the hope of bursting the bubbles. A mohair roller will be less hassle though. Thinning the paint slightly may help as well.

 

[Jupiter01]

Would these be okay?
https://www.screwfix.com/p/harris-trade-gloss-mini-roller-sleeves-multipurpose-4-x-24mm-5-pack/5519x

Does say “simulated mohair”. Was hoping to pick up from somewhere today

 

[sxturbo]

As has been said the foam roller is the problem, they are ok with oil based paints but not water based paints.

Those Harris ones will be fine

 

[opps]

Yup, they are pretty much the same as the ones in my link.

 

[Jupiter01]

Off to Screwfix. Will report back later

 

[Jupiter01]

Those rollers made a huge difference. Night and day!
No bubbles and an awesome finish. Really appreciate the advice

 

[Jupiter01]

Curious...
Why didn’t I get this issue with the MDF primer as that’s also water based?

 

[opps]

I suspect that the WB UC is much thicker and less prone to the foam injecting air in to it.

 

[Jupiter01]

UPDATE: Thanks for your help with this guys. Finished up this evening and really happy with the finish. The suggested roller made an enormous difference.

 

[sparkwright]

Looks very good.

 

[johnny2007]

Well done!

 

[opps]

Kudos