Wiping poly formulation.

[Honest John]

I'm thinking of mixing up some wiping poly after the fashion of our American cousins. They seem to use it rather a lot. I'm thinking of starting with a 1:1:1 mix of Rustins poly, BLO and White spirit as an opening gambit and make adjustments as required. I would be interested to know if anyone has tried substituting Isopropanol for white spirit? I'm thinking that it would still work as a thinner, but would flash off much quicker, allowing a faster build before setting aside to cure. I realise we are getting into the realms of chemistry here, but I am curious if anyone has tried it?

 

[ED65]

I'm thinking of mixing up some wiping poly after the fashion of our American cousins. They seem to use it rather a lot. I'm thinking of starting with a 1:1:1 mix of Rustins poly, BLO and White spirit as an opening gambit and make adjustments as required.

That'll give you the equivalent of Danish oil. If you want a wiping varnish just white spirit and the poly.

Most of what I read online suggests that a 1:1 mix is the equivalent of the typical commercial version, but I've tried diluting less (1/3 or 1/2 spirits) which works fine most of the time, and of course you get a faster build.

I don't think isopropanol is a solvent for varnish. It'll reduce BLO no problem but I think it'll cause the poly to do strange things. You could test it out but I don't think there's any benefit because it won't speed drying, that's entirely down to the poly itself and you can't speed that up with any type of thinners. Only terebine or a similar product will get the varnish to dry more quickly.

 

[Honest John]

Thanks for the reply. I had no idea that Danish oil was anything other than a mix of various oils. After reading your reply I googled Danish oil and confirmed your comments. I have used Danish oil but not for many years, although I have various finishing oils in my finish cupboard. Walnut oil from Tesco's is my latest trial and so far is looking good. I shall mix up a 50/50 mix of poly and white spirit and give it a go and see if it has any place in my armoury. Thanks again for your reply.

 

[ED65]

I had no idea that Danish oil was anything other than a mix of various oils.

One of the reasons the commercial name is so unhelpful! In case your reading didn't bring this to light "teak oil" is also a very similar product.

I shall mix up a 50/50 mix of poly and white spirit and give it a go and see if it has any place in my armoury. Thanks again for your reply.

Welcome. I've become a huge fan of wiping on varnish now that I've tried it, I'm sure you'll like it if for nothing else than it helps so much in achieving a smooth, uniform coat compared to brushing it on full-strength.

Let me pass on some other titbits on wiping varnish which I think are very helpful to know.

First is once you thin varnish to 'wiping consistency' you don't have to apply it only by wiping, it can still be applied by brush or roller if you like.

You can apply in three basic ways: apply then wipe away most of the excess, some of the excess or none of the excess. Because it's pure varnish it will always dry hard, unlike an oil/vanish mixture which will dry soft.

 

[JJ1]

A couple of good links regarding wiping varnish;


http://www.popularwoodworking.com/artic ... what-is-it


http://www.popularwoodworking.com/techn ... g_varnish2

 

[Honest John]

Thanks very much for all the excellent information in the replies. The two links to "popular woodworking" make very informative and interesting reading. I shall get some mixed up and give it a try!

 

[Fishandchips]

I finished an oak table top last year. Started with 1/2 poly and 1/2 white spirit. Gave it 6 coats in total but increased the poly content each coat until it was 100% the last coat.

You really feel like the first couple of coats are getting right into the wood because it's so thin. I must give a harder finish.

 

[Beau]

Interesting

Never read anything about this until recently but finished a pine chest many years back with what would have been termed a wiping oil. Tried brushing on the yacht varnish but found it was thicker than I wanted so tried thinning it heavily and applied with a cloth. Worked a treat but rather forgot about it and not done it since but will dabble with this again. Always used Danish and Finishing oil anyway so guess I gravitate toward this sort of finish.

 

[yetloh]

I finished an oak table top last year. Started with 1/2 poly and 1/2 white spirit. Gave it 6 coats in total but increased the poly content each coat until it was 100% the last coat.

You really feel like the first couple of coats are getting right into the wood because it's so thin. I must give a harder finish.

It's a while since I did it but I have had really excellent results with poly diluted with 40% white spiri on English oak. The final coat of about six I rubbed in with P400 wet and dry for a really lovely silky finish. It has the lustre of a waxed satin finish but has never been waxed and looks just as good years later. I have always regarded wax as a waste of time because it is so transitory; much better to get the effect you want with the finish itself and save all that re-waxing.

Jim