Water/Fat drip marks showing through paint

[gitznshiggles]

I skimmed a fireplace that id dot n dabbed a board too, but when mist coated could see the water/fat run off from my wet trowel finish on the right hand side of the fireplace.

Thought it would come out with the next coat etc but you can still see it even with top coat of emulsion....

ive not seen this before but am guessing it must be common.... bar give it a good sanding and repaint is there anything i can do? and why on this wall and not others?

 

[craigw]

shouldent really see fat,or even have fat on your wall.:RpS_thumbup:
the only time ive seen water marks showing through paint is when ive splashed PVA on new plaster by accident,before its painted:RpS_wink:

 

[gitznshiggles]

its exactly like that - a pva splash - but as far as i know that couldnt have happened... and the water run off from trowelling was all good when id finished, however when dried and painted you can see some run marks... its a bitch and has got me stumped

 

[rockhardsolidplastering]

do you use a spray bottle if not do do,it s always clean water always sprayed in exact place no splashes and you barely use any water

 

[Bagrat]

Read the back of the bag of multi or board finish .if you do as it says you won't go far wrong mate.in the latter stages etc!!!!

 

[gitznshiggles]

cheers for reply rock but yes i do use a spray bottle.. well i use a spray bottle with clean water and a 5" brush for trowelling up..

its like a run of pva but no pva-ing was done after the chimney breast, it was the last wall i did... cant work it out for the life of me

 

[gitznshiggles]

thanks Bagrat - i dont have a bag handy just at the moment - could you sum it up for me and does it mention the "unpaintable marks" im talking about?

 

[nelly]

thanks Bagrat - i dont have a bag handy just at the moment - could you sum it up for me and does it mention the "unpaintable marks" im talking about?

I think he means - It says dont use too much water.

However fat marks happen!!! especially on reskims.

I have been trying to work out why it happens, and im 99% certain its this.

The very nature of a reskim is because the walls are all over the place, when we 'trowel up' we are compressing the plaster, on deeper areas there is more to compress and this causes hollows, hollows that turn up later on in the process, which naturally get filled with fat as we are on are 2nd and 3rd trowel up.

It doesnt happen nearly as much on boards as they are much flatter to start with, which makes me think this is the reason.

Why yours wont paint is a mystery though, because fat paints just as easy as plaster.

 

[gitznshiggles]

hmm - ok well i guess its not as common as id thought then, back to the drawing boards on this one i think... ahh well thanks anyway

 

[spunky]

Use a sponge sorry

 

[spunky]

Obviously trowel it after a bit

 

[twitcher]

maybe it's cos you've ended up burnishing it a little - try sanding it and painting it

 

[spunky]

What does burnishing mean twitcher?

 

[Jace]

its brushing it with a brush of fire hence burnishing

 

[spunky]

Anyone else?

 

[smudge]

Use a sponge sorry

this bloke is a nonce spunky your f**k*d you beast

 

[Peg]

Did you take the water marks off after polishing?

 

[layiton]

What does burnishing mean twitcher?

Dry trowelling

 

[Jace]

i learn summit new every day i just call it polishing or simply dry troweling

 

[twitcher]

yeah got it off polished plastering - sounds posh don't it :RpS_wink:

 

[Chris W]

ah... but yer need a little mini pool trowel to do it proper like....
same thing though end of the day.... otherwise known as polishing, but you shouldnt really be 'poilishing'...
just a final... eggshells all yer after lads, eggshell...

 

[sshearing228]

undercoat then paintt that,ll stop the staining

 

[gitznshiggles]

ive tried mist coating then top coating etc - i think it needs a damned good sanding

 

[twitcher]

maybe it's cos the fat compressed a lot easier - cos it's thinner and there's less aggregate in it. It was compressed so much that there's no pores in the plaster and it's shiny? I reckon a bit of a sanding would do it mate too

 

[rockhardsolidplastering]

burnishing = over dry trowling when you end up with black burn marks on the finish

 

[twitcher]

just been back from quoting for a room where the geezer said the last plasterer had polished the finish so much he found it really hard to paint it. He reckons some years later that the paint has failed in places cos of this.

 

[gitznshiggles]

It wasnt over polished trust me - im strictly eggshell finish... or put another way "fek it im done" )

Id take a picture of it to show you what i mean - but you only see it when the light catches it... not a big deal but bloody annoying cos you know its there.

My next door neighbor was telling me about his recently painted bathroom wall, and how the paint was peeling in places... I asked him about his prep work before painting and somewhere along the line someone had told him to pva the finished plaster before painting...

 

[brendankelly]

just been back from quoting for a room where the geezer said the last plasterer had polished the finish so much he found it really hard to paint it. He reckons some years later that the paint has failed in places cos of this.

Firstly I have not done skimming for 25 years.
We had this problem here where every thing is skimmed with gypsum and some guys started finishing gypsum in one coat. The finishes were polished (glazed we call it) and condensation formed on the glazed areas causing the paint to fall off and mould. Architects and site project managers are now watching plasters to make sure 2 coats are applied. See more from this guy. https://www.josephlittlearchitects.com/documents/Breaking_the_Mould_4_Construct_Ireland_Issue_11_Vol_4.pdf