Varnishing gone wrong - help please.

VicS said:
Thats not the problem then, assuming you have proper white spirit to BS 245


Your tin of varnish must be very old though.
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White Spirit is from Jewsons this month.
Varnish from B&Q last month.

I will leave it outside for a while and see how it goes.
 
Ex-SolentBoy said:
White Spirit is from Jewsons this month.
Varnish from B&Q last month.

I will leave it outside for a while and see how it goes.
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Baffling !

Id not leave it outside. I'd put it in a nice warm dry room.

You'll have to do a wee test piece before proceeding with the second coat, just in case you do have a dodgy batch of varnish.

Ronseal was my usual choice of varnish for domestic stuff.

( did not think much of the water based stuff though :( )
 
Ronseal is total cr*p. Its not real varnish, the least departure from perfect conditions and it doesn't go off properly, its gloss level is dull, and its too soft to take any wear.

Scrape it all off and start again with something not bought from B&Q.
 
AndrewB said:
Ronseal is total cr*p. Its not real varnish, the least departure from perfect conditions and it doesn't go off properly, its gloss level is dull, and its too soft to take any wear.

Scrape it all off and start again with something not bought from B&Q.
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That's really not my experience.
I've used several different Ronseal varnishes in high wear areas of my house, and it is lasting well.
Including the water based stuff on our parquet kitchen floor.
Also conventional polyurethane Ronseal in a bathroom.
 
I've had this before with Ronseal exterior varnish. Was the surface largely horizontal, by any chance? If so, the coat can go on much thicker than a vertical surface coat, and it takes ages for it to harden off. Thinning the first coat by any more than 10% seems to make it worse too - possibly because it penetrates the wood well and then you have the problem of evaporating the solvents from inside the first few microns of wood fibres too.

Can you get it to to (say) 20 degrees and have ventilation? Both seem to be necessary. I've been in trouble with SWMBO before now, for bringing "smelly" bits of boat into the house but I find I have to stand them almost next to the boiler to get them to go off.

If you put another coat on now, you'll just compound the problem, but I'm pretty certain a few days in a warmer, well ventilated environment will make it turn.
 
It may be....that the brush used was not perfectly clean and contaminated the application.

I have a technique for cleaning brushes used to varnish as follows:

I take chunky glass (like a whysky tunbler) and into this I pour a 50 / 50 mix of white spirit and washing up liquid (say about 3 tablespoons of each).

Then I rotate the brush in this mix to get all the bristles right to the root affected.

Then brush under the tap to rinse off and the glass likewise.

The operation is repeated 4 or 5 times.

The bristles come out like new.

You have to make sure the fibres are separated.

Shake excess water out of brush and leave to dry naturally, works a treat, preserves brushes in top condition for years of repeated use.
 
Been using Ronseal on boat interiors for 25 years. It's the best there is. I usually find that the first coat on teak stays tacky but subsequent coats dry no problem.
 
KAM said:
Been using Ronseal on boat interiors for 25 years. It's the best there is. I usually find that the first coat on teak stays tacky but subsequent coats dry no problem.
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Oh good, I have just done the cabin steps in the satin diamond hard stuff. Colour chosen was a little dark but went on easily enough and dried quickly. Be interesting to see how it stands up.

Pete
 
I have found the ronseal stuff to work quite well. If it is not literally hours of work I would use a green abrasive scourer and go over the surface and then apply a lightly thinned coat and then a full coat or two. then let that harden and sand back. I have experienced 'soft' very thinned varnish before and this is the way I have treated it. I always assumed the high white spirit content has prevented a hard skin forming and softened the timber slightly, but probably me looking for an explanation. It is only varnish so give it ago.

But good luck all the same.
 
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Pete7 said:
Oh good, I have just done the cabin steps in the satin diamond hard stuff. Colour chosen was a little dark but went on easily enough and dried quickly. Be interesting to see how it stands up.

Pete
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I used the Diamond Hard interior stuff on Avocet's cabin sole boards a good 6 or 7 years ago now and they're great - despite having been found floating on three occasions when rainwater has filled the bilges.
 
I have been using the standard ronseal on cabin sole boards for a nmber of years. It seems to last very well. I find a tin of satin mixed with a tin of matt gives an exact match for the original finish on my boat.
 
Can't really explain why, but today it was perfectly dry.

Second coat on, so I shall report back (probably in another week!).

I think it is the low temperature in the house.
 
Ex-SolentBoy said:
Can't really explain why, but today it was perfectly dry.

Second coat on, so I shall report back (probably in another week!).

I think it is the low temperature in the house.
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Outside humidity has gone down markedly yesterday and today, all last week it was very high, certainly too high for outside decorating or varnishing.
 
I've found it quite usual with certain varnishes, over many years, that thinning the first coat (as per the instructions) often leaves a slightly tacky finish which you certainly can't sand and would be a pain to try and remove.

A second coat after a day or so, unthinned, leaves a normal surface which can be rubbed down and can give a professional finish if you do the subsequent coats properly.
 
Blue5 said:
Unless your house is hermetically sealed it will still be susceptible to outside humidity levels. From memory temperature for varnish to dry needs to be above 10c.
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I did say in the first post that it was done at 17c. That's what was puzzling. Took a week to dry.
 
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