Stained external masonry - need the ultimate stain block

[rubble2]

I have had on going problems for ages with brown stains appearing on the external masonry around the bay window of our house (it is painted white - good quality masonry paint)

Last year we were due to have the whole house painted so I decided to strip the stained paintwork down to the bare stone in an attempt to finally resolve the problem - did this, then engaged a painter to decorate the whole house exterior.

He used Sandtex masonry paint and it looked fine when first applied, but after a few days it began to visibly yellow just on the bay window area.

After recoating again with masonry paint and having the same thing happen he decied to use some Zinsser stain block when he applied this is looked ok but as soon as he applied another coat of masonry paint on top the stains re-appeared.

By this time we were running out of time weather wise (late October) so decided to leave it and see how bad it got - it got pretty bad (see picture)

Finally summoned up the enthusiasm to tackle this again a few weeks ago so spoke to the people at Zinsser and showed them the picture.

They recommended using Blackfriar anti mould treatment followed up with two coats of 'Perma white external paint' did this last weekend - looked good but now the yellowing is starting to reappear again, so it lasted 3 days.

Sorry for the long post but is there any proven method to overcome this please?

In the past I have tried oil based undercoat under the masonry paint but that didn't work either.

Now - could I try oil based gloss which I can then flat down and apply masonry paint over the top, or - thinking outside the box I even considered a flat white aerosol spray as used in car body repairs.

As you can see I am desperate here so any help would be much appreciated.

Thanks

Untitled

• rubble2
• 26 Sep 2012
• 1

Untitled

• rubble2
• 26 Sep 2012
• 1

 

[vibrobullit407]

Have you tried on oil based masonry paint like dulux weathersheild all seasons, or another pliolite masonry paint? Which zinsser product did your dec use as there are quite a few types and uses?

 

[rubble2]

Unfortunately I cannot recall for sure what product he used but I think it might have been Bullseye 123.

Not tried any other types of paint yet, do I assume from your question that the Sandtex paint is water based masonry paint and the Weathershield would have better stain resisting properties?

 

[vibrobullit407]

Unfortunately I cannot recall for sure what product he used but I think it might have been Bullseye 123.

Not tried any other types of paint yet, do I assume from your question that the Sandtex paint is water based masonry paint and the Weathershield would have better stain resisting properties?

An oil based masonry paint may stop the stain bleeding through. The all seasons is the dulux weathershield oil based paint. Not all weathershield is though. Zinsser 123 is a water based stain block an May not be right for the stain that you have.

 

[rubble2]

Thanks,

I have looked at the Zinsser website and I see that Zinsser BIN is a shellac based stain blocker, do you think that this might be more effective?

I did notice that the spec says it is suitable for spot external use - not sure what the implications are of that statement and if it would therefore not be suitable for my application.

 

[vibrobullit407]

BIN should be fine for this if you intend to use water based masonry paint. It should seal in the stain and stop the water based paint reactivating it. This is assuming that you have dealt with what ever is causing the staining!

 

[TheDec]

BIN should be fine for this if you intend to use water based masonry paint. It should seal in the stain and stop the water based paint reactivating it. This is assuming that you have dealt with what ever is causing the staining!

Really, Bin is an internal primer and only in extreme situations recomended as a spot primer for external use, perhaps the op would be better advised to lightly sand dust off and apply perhaps an alkali resistant primer.

Dec

 

[vibrobullit407]

BIN should be fine for this if you intend to use water based masonry paint. It should seal in the stain and stop the water based paint reactivating it. This is assuming that you have dealt with what ever is causing the staining!

Really, Bin is an internal primer and only in extreme situations recomended as a spot primer for external use, perhaps the op would be better advised to lightly sand dust off and apply perhaps an alkali resistant primer.

Dec

Interior and spot exterior! If this is not simply spot priming then what is? Clutching at straws comes to mind here! BIN will be fine, have used it for similar problems before with good results!

 

[TheDec]

BIN should be fine for this if you intend to use water based masonry paint. It should seal in the stain and stop the water based paint reactivating it. This is assuming that you have dealt with what ever is causing the staining!

Really, Bin is an internal primer and only in extreme situations recomended as a spot primer for external use, perhaps the op would be better advised to lightly sand dust off and apply perhaps an alkali resistant primer.

Dec

Interior and spot exterior! If this is not simply spot priming then what is? Clutching at straws comes to mind here! BIN will be fine, have used it for similar problems before with good results!

You are now starting to make yourself look and sound rather stupid.

Dec

 

[vibrobullit407]

You are now starting to make yourself look and sound rather stupid.

Dec

I am? I'll tell you what, I'll stick to using products as per the manufacturers instructions thanks! As said for this spot priming BIN will be fine!

 

[TheDec]

And may I add, that looking at the pics, do you really believe that spot priming is the answer here???? If you do, then your advice is sending the op on the road to ruin.

There are a great deal of people on here that offer advice based merely on their own experience, they dont however claim to be be something that they are not. how does that look in your minds eye!!!!!!!!!!!!!! ELROBBO

Dec

 

[vibrobullit407]

In this instance then yes, my advice is valid and will work! Just cause you have a problem with me does not mean that it will not work. Now grow up as I really can not be bothered with arguing with you all the time, it's pointless and does not help any one! I just like the way that you seem 100% certain that the salts are coming to the surface due to the masonry beneath being damp! This may not be true, it may just be a water stain from water sitting on the cill which is more plausible, hence me saying that a solvent based masonry may work in stopping the stain bleed through. The mention of the BIN was if the op was wanting to paint with a water based paint. Simples!

 

[TheDec]

In this instance then yes, my advice is valid and will work! Just cause you have a problem with me does not mean that it will not work. Now grow up as I really can not be bothered with arguing with you all the time, it's pointless and does not help any one! I just like the way that you seem 100% certain that the salts are coming to the surface due to the masonry beneath being damp! This may not be true, it may just be a water stain from water sitting on the cill which is more plausible, hence me saying that a solvent based masonry may work in stopping the stain bleed through. The mention of the BIN was if the op was wanting to paint with a water based paint. Simples!

Simples as you put it I must admit comes to mind, does that not remind you of someone.

Dec

 

[vibrobullit407]

Simples as you put it I must admit comes to mind, does that not remind you of someone.

Dec

Jealousy is a cruel mistress my friend! Now I'm off to bed, I'll check on your worthless comments tomorrow!

 

[TheDec]

Decoraters dont sleep they just meander, as said it is the finishing trade. I cant wait for your reply.

Dec