Spar Varnish?

[Shedhand]

Neil's excellent Polisher's Handbook contains a recipe for tack cloths. I go through a lot of these and at 3 bucks each I thought I'd have a go at making some myself. I bought some muslin cloth and raw linseed oil. The recipe also specifies spar varnish. Would Feast Watson Spar Varnish be appropriate? ( I ask this because Neil notes that a substitute could be polyurethane - I'm assuming that's because the Spar Varnish could be hard to come by.)
Advice gratefully received.
Cheers

[markharrison]

Spar Varnish these days is almost always a polyurethane anyway. Albeit with UV inhibitors.

You can buy real spar varnish like the Universal brand from any boat chandler like Bias. I would suggest you just try some cheapo poly or throw away stuff that has been on the shelf for too long and see how it goes. The major problem with poly is the stuff that has been on the shelf for too long either fails to go off (set) or is too thick because the solvent has evaporated from a poorly sealing lid. Neither of these conditions should be a problem for makers of tack cloths. In fact, I would expect them to be a bonus.

[Shedhand]

Thanx Mark. I ended up getting the Feast Watson and did the biz. I think the cloths turned out ok. They don't feel as 'tacky' as the shop bought ones but I'll see how they go. If it doesn't work I'll just have to buy a boat with spars and use the FW on that.:D

[durwood]

Tack cloth varnish used to be available to make tack rags but I havn't had to buy any for years as its not suitable to tack off some surfaces.

Spar varnish usually is synthetic enamel based so it can leave a trace of this on the surtface 9as can other mixtures)which you are going to paint. A lot of the new paints react with it and spoil you paint finish. There are special ones made for the auto trade usually because 2 pack finishes react. Often you have to get speciafic brands of tack cloth for particular brands of paint to avoid the problem. Try the tack rag on a testsurface before you wipe over and paint something you have just spent hours getting prepared. Anything with linseed oil it it would only be suitable for turps thinned paints.

All 2 pack paints have a shelf life of only 12 - 24 months max and then they are useless. Often in auto shops the lesser used itinters go off on the mixing machine before you can use the.

[Shedhand]

Tack cloth varnish used to be available to make tack rags but I havn't had to buy any for years as its not suitable to tack off some surfaces.

Spar varnish usually is synthetic enamel based so it can leave a trace of this on the surtface 9as can other mixtures)which you are going to paint. A lot of the new paints react with it and spoil you paint finish. There are special ones made for the auto trade usually because 2 pack finishes react. Often you have to get speciafic brands of tack cloth for particular brands of paint to avoid the problem. Try the tack rag on a testsurface before you wipe over and paint something you have just spent hours getting prepared. Anything with linseed oil it it would only be suitable for turps thinned paints.
Hmm...interesting. The tack cloths I've been buying are usually in the automotive paints section of the local 3D Paints shop. They are very good for removing all the dust off sanded woodwork. I don't paint anything much (mainly because I loathe - and I mean LOATHE painting :mad: ) but I do a fair bit of French Polishing. I haven't had any problem's with tack residue so far. I am having second thoughts about the cloths I made however. I wonder if Feast Watson Spar Varnish is unsuitable. Maybe thats why it didn't feel as tacky?:confused:
Cheers

[durwood]

the idea behind a tack rag is that it stays tacky, most normal varnishes would be made to dry. you need to use something which won't dry if left exposed to the air, the poly would sort of do that as it needs hardener.

The tack rag varnish has the drying agent left out of it, from memory its called terebine, you could buy it to help speed up the drying on enamel if you needed to do so.

Wiping off dust on wood would not be a problem whatever you use, but I would give it a final blow with compressed air if you can.Again putting shellac over the timber would be pretty save as the metho is not really strong enough to stur things up.

I didn't explain what actually happens with the tack rag on the paint, when you paint over the wiped surface the wipe marks show up exactly as you did them.Wipe the tack rag on the surface and write your name and you get it showing up in the finished paint.

[Shedhand]

Thanks for the info Durwood. Greenie your way...
Grateful. I think I'll just continue to buy them pre-made.
Cheers