Blending in Blistered paint

[OhGranny]

Hi
I have some rather large Blisters to remove from fairly thick coats of paint and re-paint over.
I don't really want to strip or burn the whole lot off.
What is the best way to "Fill" the area where the blisters are removed so there is not so much visible difference in the thickness of the paint?
I tried once before with filler but it was a lot of work to spread as thin as the paint and rub down and as this is outside I am worried that the filler will lift off with weathering.

Thanks
g.

 

[Donkii]

I am no pro but I am going to tell you what u dont want to hear....... strip it all off. When we moved into our new home I was painting the bathroom and some areas started to blister. I like you tried to just peel off the blitered areas and fill them in. No matter how much I tried it just wasnt a pleasing job so I just lost the plot and stripped the lot, didnt need a burner just a good scraper and the wife to help. had it all done in one night and applied the mist coat the next morning.

 

[sparkwright]

Sounds like your work is outside, so appearance may not be as important as inside would be.

Scrape all the loose paint off, and 'feather' the raised edges with sandpaper best you can. Treat any knots and prime any bare wood.

If the raised edges still look very obvious, 'skim' over the patches with a two part wood filler. Remove excess before it sets. Sand. Refill if necessary.

 

[oldgreymouse]

Without a doubt, the correct method is to remove all the paint as I am guessing this is exterior paint over wood work. The blisters can happen after many coats of paint have been added over the years and it then separates away from the very first original primer coat. Hot sun on old garage doors springs to mind.
A similar thing happens with paint kettles, you use them for months on end, never quite cleaning all the paint out, then all of a sudden they start cracking on the inside, bash it all off and hey presto, a nice clean plastic paint kettle again!!

If however you do not want to remove all the other paint then one other method is to use a the two pack filler but make sure you get the 'Easy Sand' as you will never get the usual two pack filler to sand off very easy, accept if you happen to have an angle grinder and heavy duty sanding discs!!
Apply in small amounts, feather in the edges then apply an oil based, not water based, undercoat. Flat down when dry, apply second u/c then top coat.

 

[OhGranny]

Yes it it a garage door and the woodwork been painted over and over.
Can you still get gas or parrafin blowtorches?
I have used a heat gun before but I found it rather slow and paint stripper costs a fortune and is really messy.
Thanks for the advice.
G.

 

[oldgreymouse]

To be honest, if you are going to try and remove all the paint back to bare wood and you do not own a proper gas blowtorch with a wide flat nozzel, then hire one!
If you use those small handy gas refills on a gun at £4 to £5 a pop, then you may need a pile of these and you may not be so lucky as to find a blowtorch in a diy store with the wide paint stripping nozzel.

Ring round a couple of hire shops and see whats about. To do a set of garage doors you will need the red gas cylinder that is just a bit bigger than the size of a football. ( Not sure how many kilograms of gas these are)
Allow a working time of about one and a half hours per door, with no wind!
Start at the bottom of the door on your knees and work up each T & G board. Don't be tempted to start in the middle standing up as you will waste time and gas.
Don't try burning downwards, heat rises so keep the flame above and the scraper blade sliding up from below. You will soon learn how much time to keep the flame on to melt the paint.
Also don't bother with burning off all the little bits, get the bulk of it stripped off and do any little bits last.
Beware! knots in the wood will become active again after heat.

 

[joe-90]

Just fill them with car body filler. No need to fart about all weekend stripping, priming, undercoating glossing. What a waste of time.

 

[paulandfrodo]

Jo-90... Yep a painter and decorator told me about car body filler.. Next time I need to do any filling I won't but that rather expensive ronseal two part mixer stuff I'll spend my money on car body filler. Big old tin for I think £24 ish... He said he gets through two of those a year and saves big time.