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Ronseal Matt Varnish

Posted: Thu Oct 29, 2009 4:25 pm
by davebooth
I have recently purchased a tin of Ronseal matt varnish.
I have used this many times in the past but this new tin is giving me a slightly white finish if applied by airbrush. I thin 50:50 with white spirit normally but I have also thinned with acetone thinner and never had this 'white' finish before.
I have tried both thinners with the new stuff but get this white blooming with either. However, brush applied the stuff dries the usual clear matt. I tried it neat with a Humbrol cheapo airbrush which, with maximum through-put of air managed to spray the neat varnish OK and this too has dried without the white bloom, so it would appear to have something to do with thinning the varnish.
I don't think that my better airbrush will push through the neat varnish and I really need the finer control and smaller spray pattern that the better brush gives.
Any ideas please?

Re: Ronseal Matt Varnish

Posted: Fri Oct 30, 2009 10:08 pm
by Flymo748
davebooth wrote:I have recently purchased a tin of Ronseal matt varnish.
I have used this many times in the past but this new tin is giving me a slightly white finish if applied by airbrush. I thin 50:50 with white spirit normally but I have also thinned with acetone thinner and never had this 'white' finish before.
I have tried both thinners with the new stuff but get this white blooming with either. However, brush applied the stuff dries the usual clear matt. I tried it neat with a Humbrol cheapo airbrush which, with maximum through-put of air managed to spray the neat varnish OK and this too has dried without the white bloom, so it would appear to have something to do with thinning the varnish.
I don't think that my better airbrush will push through the neat varnish and I really need the finer control and smaller spray pattern that the better brush gives.
Any ideas please?

They've changed the formulation?

You don't say exactly what product it is, but the product data sheet for the Quick Drying Matt Varnish says that it's water-based.

http://www.ronseal.co.uk/datasheets/ron ... arnish.pdf

If you're expecting it to be oilbased, and therefore used thinners or acetone, it will have formed a suspension of varnish particles rather than being thinned down. It's probably the way that it dries that makes the difference to the finish.

HTH
Flymo

Re: Ronseal Matt Varnish

Posted: Sat Oct 31, 2009 10:51 am
by Will L
Flymo748 wrote:They've changed the formulation?

You don't say exactly what product it is, but the product data sheet for the Quick Drying Matt Varnish says that it's water-based.

http://www.ronseal.co.uk/datasheets/ron ... arnish.pdf

If you're expecting it to be oilbased, and therefore used thinners or acetone, it will have formed a suspension of varnish particles rather than being thinned down. It's probably the way that it dries that makes the difference to the finish.
Flymo


That makes sense I was going to say that you can get the same result (milky finish) if you contaminate the old formula with water!! (e.g. spraying on a very humid day and not using a moisture trap)

Will

Re: Ronseal Matt Varnish

Posted: Sat Oct 31, 2009 11:01 am
by Will L
As I sit here there is a program on radio 4 about Izal medicated toilet tissue which were medicated with tar extract disinfectant.

Why is that relevant here?

Well the company that produced Izal disinfectant also obtained Ronseal form from the same source, which they said "is still in use today". Little did they know!

Will

(radio 4 " Now Wash Your Hands" 9:30 to 10:00 Saturday 31st October. Presumably you can listen again)

P.S. I notice this forum is still on summer time!

Re: Ronseal Matt Varnish

Posted: Sat Oct 31, 2009 6:21 pm
by Tim V
Forum time is changed via your profile. Is it worth it, another six months and you have to change it back :!:

Re: Ronseal Matt Varnish

Posted: Sat Oct 31, 2009 10:52 pm
by grovenor-2685
Forum time is changed via your profile. Is it worth it, another six months and you have to change it back :!:

Well almost, actually 'User Control Panel" - 'Board Preferences' tab.
Keith

Re: Ronseal Matt Varnish

Posted: Wed Nov 04, 2009 4:35 pm
by davebooth
Flymo748 wrote:
davebooth wrote:I have recently purchased a tin of Ronseal matt varnish.
I have used this many times in the past but this new tin is giving me a slightly white finish if applied by airbrush. I thin 50:50 with white spirit normally but I have also thinned with acetone thinner and never had this 'white' finish before.
I have tried both thinners with the new stuff but get this white blooming with either. However, brush applied the stuff dries the usual clear matt. I tried it neat with a Humbrol cheapo airbrush which, with maximum through-put of air managed to spray the neat varnish OK and this too has dried without the white bloom, so it would appear to have something to do with thinning the varnish.
I don't think that my better airbrush will push through the neat varnish and I really need the finer control and smaller spray pattern that the better brush gives.
Any ideas please?

They've changed the formulation?

You don't say exactly what product it is, but the product data sheet for the Quick Drying Matt Varnish says that it's water-based.

http://www.ronseal.co.uk/datasheets/ron ... arnish.pdf

If you're expecting it to be oilbased, and therefore used thinners or acetone, it will have formed a suspension of varnish particles rather than being thinned down. It's probably the way that it dries that makes the difference to the finish.

HTH
Flymo


The tin says:

Ultra tough Mattcoat Polyurethane, interior clear varnish.

The web site says:
Ronseal Clear Varnish is a low viscosity,
polyurethane based varnish in essentially
aliphatic hydrocarbon solvent. Ronseal Clear
Varnish contains no free isocyanates.
And:
Spray Application
For conventional spraying equipment with a
nozzle giving a normal fan, no dilution with
solvent is required. However, spray gun
manufacturer’s advice should be followed and
dilution up to a maximum of 10% white spirit
will achieve the required viscosity in most
cases.

My compressor has a water trap and I was spraying in the workshop with the heating on and the day was neither wet nor particularly cold.
However, While I used white spirit I did exceed the 10% so I'll try it with "up to 10%