Alternatives to Thistle Bond It to plaster over Moisture Resistant plasterboard.

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paolonline

New Member
I have moisture resistant plasterboard (about 4.5 square metres of it, i.e. about 2 full boards) in a bathroom and need to plaster over it.
How would you prime it to guarantee adhesion?
The recommended product is Thistle Bond it, of course, which is priced at £75 for 10 litres of the stuff, when I'd need only 1 litre for my needs.
Any cheaper but suitable alternatives out there?
Would Blue Grit do?
Any suggestion would be much appreciated.
 

jamesthefirst

Private Member
I have moisture resistant plasterboard (about 4.5 square metres of it, i.e. about 2 full boards) in a bathroom and need to plaster over it.
How would you prime it to guarantee adhesion?
The recommended product is Thistle Bond it, of course, which is priced at £75 for 10 litres of the stuff, when I'd need only 1 litre for my needs.
Any cheaper but suitable alternatives out there?
Would Blue Grit do?
Any suggestion would be much appreciated.
A lot of the lads on here will say just skim it they have ha no failures which is fair enough but you may as well do as the spec says on your own house. If youhave a Wickes they do a small tub of bonding agent which you can use, we use the 25kg version for around £60 yours will be around £18 I think. Give it a good stir with a scraper or similar to get the grit to mix in with the liquid.
Skim in about 4 hours or next day.
 

themucky1

Well-Known Member
I have moisture resistant plasterboard (about 4.5 square metres of it, i.e. about 2 full boards) in a bathroom and need to plaster over it.
How would you prime it to guarantee adhesion?
The recommended product is Thistle Bond it, of course, which is priced at £75 for 10 litres of the stuff, when I'd need only 1 litre for my needs.
Any cheaper but suitable alternatives out there?
Would Blue Grit do?
Any suggestion would be much appreciated.
So in your opinion the cost of £75 is too much for something that’s recommended regardless of quantity used?
 

Djr

Well-Known Member
It's a fair point. £75 to prep 2 boards? I've never prepped a single moisture resistant board. Including in my own house. If you really want slap abit of PVA on but grit isn't needed
Yes skim thousands of mtrs of them without grit and been fine
 

themucky1

Well-Known Member
Yes skim thousands of mtrs of them without grit and been fine
So have I and I’ve never had a problem, but he wants price of mind that the skimming will adhere and what’s £75 for piece of mind? Not a lot in the grand scheme of things
 

themucky1

Well-Known Member
I have moisture resistant plasterboard (about 4.5 square metres of it, i.e. about 2 full boards) in a bathroom and need to plaster over it.
How would you prime it to guarantee adhesion?
The recommended product is Thistle Bond it, of course, which is priced at £75 for 10 litres of the stuff, when I'd need only 1 litre for my needs.
Any cheaper but suitable alternatives out there?
Would Blue Grit do?
Any suggestion would be much appreciated.
You’ll get thistle bond it for less than £75
 

Robbo123

Well-Known Member
So have I and I’ve never had a problem, but he wants price of mind that the skimming will adhere and what’s £75 for piece of mind? Not a lot in the grand scheme of things
He came on asking if there was an alternative though. Which there is. Cheaper Wickes version for £18 or PVA, or don't bother with either like 9/10 plasterers do
 

Robbo123

Well-Known Member
I have moisture resistant plasterboard (about 4.5 square metres of it, i.e. about 2 full boards) in a bathroom and need to plaster over it.
How would you prime it to guarantee adhesion?
The recommended product is Thistle Bond it, of course, which is priced at £75 for 10 litres of the stuff, when I'd need only 1 litre for my needs.
Any cheaper but suitable alternatives out there?
Would Blue Grit do?
Any suggestion would be much appreciated.
Out of interest is the area in question being tiled or painted? If it's being tiled you don't need to plaster at all
 

bof

Well-Known Member
Agree with all of you but here's a method for extra grab

Can't upload video @Danny so here's a picture
15792649354028138216772238963364.jpg


Loosely hold Stanley blade and rasp across the surface
 

jamesthefirst

Private Member
He came on asking if there was an alternative though. Which there is. Cheaper Wickes version for £18 or PVA, or don't bother with either like 9/10 plasterers do
I thought you liked to do things properly or by the book? BG spec is grit not pva or have they changed their minds again lol! :p
 

bof

Well-Known Member
I thought you liked to do things properly or by the book? BG spec is grit not pva or have they changed their minds again lol! :p
It does say grit , but have done a few with mo problems , wouldn't want to hang tiles on it though
 

Robbo123

Well-Known Member
I thought you liked to do things properly or by the book? BG spec is grit not pva or have they changed their minds again lol! :p
Properly when it needs to be done properly. If you followed what BG says then you wouldn't even be able to mix their plaster
 

jamesthefirst

Private Member
Properly when it needs to be done properly. If you followed what BG says then you wouldn't even be able to mix their plaster
I can’t understand why they didn’t just add the unifinish ingredients to normal multi and just call it new improved With use of pva on very high suction. Then non of this nonsense as you could just slap it on virtually anything or still use a bit of pva if you liked.
 

Vincey

Private Member
If it’s being skimmed has to be thistle bond it but zombie (you DOSSER) is right Unifinish would of been ok to go straight on as it was polymer enhanced
 

Vincey

Private Member
Can’t remember exactly why they say to thistle bond it think it’s the paper and the core that are both different to standard boards which is why it’s spec

C212FC6E-19DF-4594-8DE4-DDC8695E4A8B.jpeg
 

paolonline

New Member
Thanks for all the reply, guys.
Very informative (and some quite funny too!).
My first take is that (as Jamesthefirst had forecast) different plasterers would use different primers/bonding agents (or none) for the same job. All successfully.
Some would use PVA (usually my preferred choice), some BG, some Bond It, some no bonding agent at all. And all would swear by their own strategy.
I guess these days materials are versatile enough to work well under many different conditions and on backgrounds with different suctions.
It is at same time reassuring (you can't really go wrong) and worrying (there's no golden rule to get it right! It's up to you to get a good job, with your strategy/marerial of choice).

In reply to other specific questions: in the grand scheme of things £75 is not much to get peace of mind and get it right. But here we're talking about small scheme: less than 2 boards. A 10 litre tub of Bond It would cover 45 sqm. So I'd be using just about 1 litre of Bond It, and keep the remaining 9 litres (£67 or so of it) stored away somewhere, waiting for the next opportunity to use the stuff! I don't like the inconvenience. That's why I asked about cheaper alternatives. BG seems a suitable one, I think I'll go for that (even for the sake of experimentation).
As for the MR boards, I regretted choosing them shortly after putting them up, but I didn't want to scrap what I'd already done.
Things you learn.
Thanks again, guys, for all your input!
 

carl-the-plasterer

Well-Known Member
Can’t remember exactly why they say to thistle bond it think it’s the paper and the core that are both different to standard boards which is why it’s spec

View attachment 44067
MR boards contain silicone in the paper/board to make them water resistant which is why they recommend if you're going to put skim on them to pre-treat with thistle bond-it to give mechanical key for plaster. although as I said previously in this thread utterly pointless skimming them as you take away the whole point of them being moisture resistant.
 

Vincey

Private Member
MR boards contain silicone in the paper/board to make them water resistant which is why they recommend if you're going to put skim on them to pre-treat with thistle bond-it to give mechanical key for plaster. although as I said previously in this thread utterly pointless skimming them as you take away the whole point of them being moisture resistant.
Nice one , I hardly ever use them mate was just trying to give him the facts , looks like he’ll just do a bodge job anyway as most do nowadays, bg don’t just give spec for no reasons everything is tested in labs that’s why they say what they do up to him if he doesn’t
There have been posts in the past where other grits peel off the walls I seen that’s why I don’t bother using the shitter cheap grits
 

The Hobo

Well-Known Member
I have moisture resistant plasterboard (about 4.5 square metres of it, i.e. about 2 full boards) in a bathroom and need to plaster over it.
How would you prime it to guarantee adhesion?
The recommended product is Thistle Bond it, of course, which is priced at £75 for 10 litres of the stuff, when I'd need only 1 litre for my needs.
Any cheaper but suitable alternatives out there?
Would Blue Grit do?
Any suggestion would be much appreciated.
50/50 sbr
 

The Hobo

Well-Known Member
MR boards contain silicone in the paper/board to make them water resistant which is why they recommend if you're going to put skim on them to pre-treat with thistle bond-it to give mechanical key for plaster. although as I said previously in this thread utterly pointless skimming them as you take away the whole point of them being moisture resistant.
I have heard that to some architects still want it
 

paolonline

New Member
Hi there, thanks again to all of you folks who contributed to this thread.
In the end I did buy and use Blue Grit for half of my moisture resistant wall, and used good old PVA for the other half.
For research purposes.
And in my experience the winner was... PVA!
I can't fault PVA.
Cheaper than Blue Grit, and easier to work on, even on green plasterboard (which I will not use. Ever. Again).
So, for the benefit of future posters on this topic, these are my personal conclusions from my experience:
1. Never use moisture-resistant plasterboard;
2. If it's there, and happens to need to be plastered, PVA it like everything else, and you'll be absolutely fine;
3. Don't waste money or time on Blue Grit, Thistle Bond it or anything else, PVA will do it.
Cheers
 
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John j

Mono Don
Hi there, thanks again to all of you folks who contributed to this thread.
In the end I did buy and use Blue Grit for half of my moisture resistant wall, and used good old PVA for the other half.
For research purposes.
And in my experience the winner was... PVA!
I can't fault PVA.
Cheaper than Blue Grit, and easier to work on, even on green plasterboard (which I will not use. Ever. Again).
So, for the benefit of future posters on this topic, these are my personal conclusions from my experience:
1. Never use moisture-resistant plasterboard;
2. If it's there, and happens to need to be plastered, PVA it like everything else, and you'll be absolutely fine;
3. Don't waste money or time on Blue Grit, Thistle Bond it or anything else, PVA will do it.
Cheers
Why never use em
 

tapit

Well-Known Member
I believe that the paper is the same just a different colour.
The glue to stick the paper may be different.
Bond it,is prob recommended to increase profits.
This is just my theory and it could be a conspiracy.
 

John j

Mono Don
I.ve never even pvad moisture boards when I.ve been asked to skim em. Never any come back.. only time I.ll pva a board is if it's been up bout 6 month
 
I have moisture resistant plasterboard (about 4.5 square metres of it, i.e. about 2 full boards) in a bathroom and need to plaster over it.
How would you prime it to guarantee adhesion?
The recommended product is Thistle Bond it, of course, which is priced at £75 for 10 litres of the stuff, when I'd need only 1 litre for my needs.
Any cheaper but suitable alternatives out there?
Would Blue Grit do?
Any suggestion would be much appreciated.
If you want to cut corners to save some money which is understandable you might as well just skim it.ive skimmed thousands of bathrooms without priming them.
 
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