Bedec MSP and oil-based primer?

[Rosarindo]

Hello

I’ve stripped some Victorian sash windows and wanted to paint them with Bedec MSP.

However, I will need to use an oil-based primer underneath and on top of the new putty - I was going to use Zinsser BIN.

(The putty I’ve bought is Toupret Glazing Putty).

Will this work? I called Bedec and they said they wouldn’t advise doing that, but I don’t know what else to do other than leaving the putty bare.

There’s also some residual lead paint (and varnish) on there which didn’t come off with the stripper/scraping/sanding - it’s not flaky, so I’d rather just paint over it. Will that affect adhesion or will Bedec MSP be alright over that? I’ve attached photos to show what I mean.

In short: can I use Bedec MSP over Zinsser BIN and old lead paint even though they’re both oil-based?

They are south-facing windows and not in the best condition - paint has never lasted on them in the past, so I’d like to get it right this time!

Thanks

 

[noj]

Zin BIN is basically shellac in a very volatile solvent rather than an oil based paint, absolutely no issues using it externally under MSP on South facing materials (in my experience)

 

[Toby Newell]

Hello

I’ve stripped some Victorian sash windows and wanted to paint them with Bedec MSP.

You mean you have nearly stripped them.

However, I will need to use an oil-based primer underneath and on top of the new putty - I was going to use Zinsser BIN.

Zinsser BIN isn't an oil based primer, it's shellac based and the solvent is alcohol, this won't work with oil putty. Use an oil based (alkyd) primer.

(The putty I’ve bought is Toupret Glazing Putty).

Will this work? I called Bedec and they said they wouldn’t advise doing that, but I don’t know what else to do other than leaving the putty bare.

There’s also some residual lead paint (and varnish) on there which didn’t come off with the stripper/scraping/sanding - it’s not flaky, so I’d rather just paint over it. Will that affect adhesion or will Bedec MSP be alright over that? I’ve attached photos to show what I mean.

Yes. It could affect adhesion, you always risk your new coating if you fail to strip clean.

In short: can I use Bedec MSP over Zinsser BIN and old lead paint even though they’re both oil-based?

Strip your timber clean, adhesion is very depenedant on surface preparation.

Use an oil based primer or linseed oil diluted 20% with turps under the putty. You can coat after 6 weeks. Bedec is an alkyd / acrylic hybrid, it goes over most stuff but putty needs to have a dry skin and that can take months.

They are south-facing windows and not in the best condition - paint has never lasted on them in the past, so I’d like to get it right this time!

Thanks

 

[Toby Newell]

You could ask Toupret if their putty contains driers or other siccatives. Putty made with basic raw linseed oil can take months to dry. You could try a very thin coating of an oil based paint on the putty, then when that dries (about 6 days) you could put MSP over that. Things like puttying are very hit and miss. A putty with a lot of driers cures faster but isn't as durable so there is an element of trial and error to a lot of traditional finishes.

 

[Feltwell]

Heresy alert - why not use a modern putty replacement. It will last longer than linseed putty and you can paint over it with MSP straight away. Get yourself a Palu tooling block would be my top tip if you go down this route. It can all be cut out again in the future if glass needs replacing or whatever, just as with linseed putty. I've found RepairCare Dry Seal MP to be the best.

Old article with more info here:- https://www.periodproperty.co.uk/fo...-repair-dont-replace.16963/page-2#post-229756

 

[Toby Newell]

Heresy alert - why not use a modern putty replacement. It will last longer than linseed putty and you can paint over it with MSP straight away. Get yourself a Palu tooling block would be my top tip if you go down this route. It can all be cut out again in the future if glass needs replacing or whatever, just as with linseed putty. I've found RepairCare Dry Seal MP to be the best.

Old article with more info here:- https://www.periodproperty.co.uk/fo...-repair-dont-replace.16963/page-2#post-229756

Wow. They using MS hybrids as putty now. So that's basically all non bitumen compatible flooring adhesives, pretty much all construction adhesives, a large chunk of sealants and now putty.

 

[mardinor]

Seconded. Scrape out the putty and use RepairCare Dry Seal MP instead. Far superior. Alternative tool is Fugi silicone set - don't use a finger or fairy liquid! MultiSolve is your friend to smooth - works for all MS hybrids and makes working with them much easier.

 

[Rosarindo]

You mean you have nearly stripped them.


Zinsser BIN isn't an oil based primer, it's shellac based and the solvent is alcohol, this won't work with oil putty. Use an oil based (alkyd) primer.


Yes. It could affect adhesion, you always risk your new coating if you fail to strip clean.


Strip your timber clean, adhesion is very depenedant on surface preparation.

Use an oil based primer or linseed oil diluted 20% with turps under the putty. You can coat after 6 weeks. Bedec is an alkyd / acrylic hybrid, it goes over most stuff but putty needs to have a dry skin and that can take months.

Arghhh. Does that mean I can’t use Zinsser Bin underneath trowel mastic? (I’m using Everbuild 103 Trowel Mastic) - it’s linseed oil based.

I’ve just prepped the timber with it where the trowel mastic is going to be. I thought it was oil-based. Will it be alright? Should I paint over the top of the Zinsser Bin with Zinsser Cover Stain (oil-based)?

I’ve been stripping the window with a heat gun and I feel uneasy about the lead dust getting treaded back into the house. That's why I wanted to stop there. But I take your point about the adhesion.

I know people use paint stripper but it looks so messy and I’m worried I won’t neutralise it properly before painting. I’ve never done this before, so I don’t know how to do it properly.

 

[Rosarindo]

Heresy alert - why not use a modern putty replacement. It will last longer than linseed putty and you can paint over it with MSP straight away. Get yourself a Palu tooling block would be my top tip if you go down this route. It can all be cut out again in the future if glass needs replacing or whatever, just as with linseed putty. I've found RepairCare Dry Seal MP to be the best.

Old article with more info here:- https://www.periodproperty.co.uk/fo...-repair-dont-replace.16963/page-2#post-229756

Thank you for the recommendation - I try to do things traditionally, but I’m happy to use a modern substitute if it’s actually a better product!