Idiot's guide to shellac needed

[billw]

Hi

Just mixed up my first batch of shellac flakes and now they've all dissolved I've had trouble finding some definitive guide to applying it successfully. It looks like applying it with a brush will suffice, and 3 or 4 coats should be enough before a final polish with beeswax.

However what I don't know is whether it needs sanding down between coats? Do I need to strain the shellac before use (it was a 250g pack of Liberon blonde dewaxed, mixed with 1 litre of meths) or can I apply it straight on? What's the optimum time to leave between coats?

I've got some 0000 grade steel wool but by the looks of it this should only be used right at the end before polishing, rather than between coats.

Cheers in advance

 

[yetloh]

Hi

Just mixed up my first batch of shellac flakes and now they've all dissolved I've had trouble finding some definitive guide to applying it successfully. It looks like applying it with a brush will suffice, and 3 or 4 coats should be enough before a final polish with beeswax.

However what I don't know is whether it needs sanding down between coats? Do I need to strain the shellac before use (it was a 250g pack of Liberon blonde dewaxed, mixed with 1 litre of meths) or can I apply it straight on? What's the optimum time to leave between coats?

I've got some 0000 grade steel wool but by the looks of it this should only be used right at the end before polishing, rather than between coats.

Cheers in advance

I never strain mine becayse any bits left tend to sink to the bottom and dissolve over time anyway. I tend to apply it with a cloth which saves the faff of cleaning brushes. You will probably find the first coat raises the grain slightly, just cut back with a fine paper between coats. If you use your wire wool after the last coat and then burnish vigorously with a soft cloth you will get a nice soft sheen which doesn't need waxing.

Jim

 

[Matt@]

depends on what you are polishing as to what method to use. Common mistake in mixing up your own is applying too thick ie mixing it too thick. Brushing it on is ok if its not too thick and the first coat will look the best but with subsequent coats looking worser the more you put on if you are doing say a flat expanse! Best way is to lay it on with a rubber doing one coat at a time and leaving each coat 10 minutes. First coat should be flatted with say 400g paper. Subsequent coats shouldnt need flatting. Apply the polish in straight lines taking care not to leave ridges of surplus polish (rubber too wet) Obviously if you are well practiced then apply the polish continually and dont leave 10mins between coats. Biggest mistake a beginner can make is to rush things with subsequent applications of polish ripping the preceeding one up cos its not had long enough to form a hardish skin. If you are polishing things like chair legs then brush coating works better but leave 30mins between coats. I would use the 0000 right at the end then wax and use paper in between coats if necessary.

 

[billw]

Thanks for the help - googled how to make a rubber and couldn't get anything with pictures and the text descriptions made it look fiddly.

Will have a go with a brush and some 400 grit paper on a test piece or two.

 

[MIGNAL]

Brushing on Shellac is basically known as Spirit varnishing. It requires a degree of practice to get good at it but there are a few tips that can help you along the way.
Use a decent brush, preferably an Ox/cattle hair or better. As Matt says, apply it thin - watery thin. You can't brush out as you would with an oil based varnish. You have two or three strokes on the same 'band'. Don't go back if you've missed an area, it will only make things worse. You can add a few drops of spike oil of Lavender and/or put the Shellac in the fridge to extend the brushing time a little.
For a full gloss finish you may have to apply as many as 15 coats. I probably apply 5 coats before I do any rubbing down. That's because there isn't much point in taking off what you have just put on. However if the Shellac has been applied unevenly then there is little option.
It takes me around 5 days to apply 15 coats. The final leveling and polishing is done some 3 or 4 weeks later when things have truly hardened off.
Practice. There is no substitute. You have to work quickly (without rushing) and confidently. The skill level required is no different than French Polishing. You can obtain a very fine glossy finish if you go through the grits and polishing compounds.

 

[billw]

Great stuff, thanks, I'll put a few coats on and then see how I've got on. I think it'll be a case of using quite a few test pieces before I dare move onto doing a real piece.

The shellac is mixed 250g flakes to 1 litre of meths, and it's pretty watery.

 

[milkman]

Rubber: you need two squares of clean old cotton cloth. Fold the corners of one square in on themselves to make up a ball. Dip it in the shellac and place on the second square. Gather the corners up over the ball and twist it so you have a ball shape with a neck that you can hold, the 'rubber'.
You can now twist the rubber to squeeze out more shellac onto its face. Seem to remember a very small drop of linseed is recommended on this face. Not sure why.
If you run out just take the ball out and recharge it with shellac.
I've found that the shellac runs out quickly. Maybe a ball made of webbed cotton, like tack cloth is made from, would be better.
I'm still trying to get this right myself but I have found you have to be bold and not worry about mistakes when you’re applying it. If it cocks up you just have to take it on the chin, clean up and have another go.
Do this a lot on scraps before you try it on your workpiece!

 

[billw]

Sounds easy enough will try that although have been using a brush and it's looking not too bad at all.

 

[wcndave]

I applied french polish a while back, which i think is a thick cut of shellac in essence and put cotton wool in the middle rather than another cloth.

I mixed my first batch from flakes yesterday, using denatured alcohol rather than meths. I did a 3 pound cut, enough to last 3 months and then will dilute to a 1.5 pound cut for use. There is a calculator for this at woodshopwidget.com i think.

I have got a bit bored with making rubbers, and now i just apply with a cloth. I use a fairly thin mix for that, but then i tend to use as a sealer, or between coats of different other finishes due to its natural binding properties.

I tend to put either oil, poly, or water varnish on top. My latest effort had shellac sealer, melamine lacquer, friction polish and then burnishing cream on top, came out great.

So i think its really flexible and versatile, which means there are no hard and fast rules for getting it down, whatever works. Too thick makes it harder, i think i would only use a proper rubber if doing a complete shellac finish... So makes my life easier ;-)

 

[billw]

Have realised that cleaning the brushes afterwards is an absolute faff, will attempt to apply using cloth next I think. Only doing some relatively small surfaces and they're bad enough so I'd dread to think how hard it would be to brush the table top that's next on the list.

My first attempts have proven mixed, some of it looks alright, some of it needs a bit of corrective action. At least I can just sand the whole lot off and start again if need be.

There's three woods in the piece - the bog oak took just two coats to come up to a fantastic shine and it applied very evenly. The black walnut (treated with boiled linseed oil) has had 3 coats and still doesn't look quite right, and the maple is on coat 4 and looks absolutely nowhere near finished.

 

[Sawyer]

Have realised that cleaning the brushes afterwards is an absolute faff, .

If you have a brush used exclusively for this, you don't really need to. It'll go hard, but next time you use it, just let it soak in the polish for a few minutes and the brush will be fine.

 

[Matt@]

Have realised that cleaning the brushes afterwards is an absolute faff, .

If you have a brush used exclusively for this, you don't really need to. It'll go hard, but next time you use it, just let it soak in the polish for a few minutes and the brush will be fine.

thats incorrect really. Any brush that hasnt been washed that has hardened shellac polish on it will take at least half a day in a solvent like meths to soften up. Letting it stand in polish will just produce a horriible sticky mess unless you leave it in for days. Washing them isnt a faff at all - just get a glass jar, pour an inch of meths in, soak the brush and dry it out with some clean cloth then chuck the meths and replace and repeat process 3 times.

 

[MIGNAL]

Not my experience at all and I've done a lot of Spirit varnishing. All you really need is a jar of spirit that you use to soften the brush. Doesn't matter if it gets contaminated with Shellac, it will still be a very dilute solution. Just suspend it for an hour or so and it should be soft enough to use. I haven't washed a spirit brush out in years!

 

[Newbie_Neil]

Use something like a jam jar and make a hole in the lid. You then drill a hole in the brush handle and insert a small rod. When the brush is pushed through the hole in the lid the rod stops it reaching the bottom of the jar. Now all you need to do is to cover the bristles with spirit.

I hope that I've explained this clearly.

You need to use a polishing mop and wadding inside the rubber.

Thanks,
Neil

 

[MIGNAL]

. . . or one of the flat cattle hair bristle brushes. I think Liberon do them, although I have no direct experience of their version. The brush that I use was bought from one of the Violin makers suppliers and it's certainly good enough for laying down shellac. I also have a sable/synthetic mix brush that is very good but at 1 inch wide it's only really useful for detail.
I bought one of the synthetic 'Golden taklon' brushes that some folk rave about. I couldn't get on with it. It doesn't seem to hold nowhere near the same amount of Shellac as the other brushes do, which means you are dipping the brush much more frequently.
If you intend to brush Shellac on your projects it really is worth buying a good quality brush. They last years if not decades.

http://www.youtube.com/watch?v=fZ9M-B79jzs

 

[billw]

I've just left the brush in white spirit (yes I realise that it doesn't dissolve the shellac, but it keeps it damp enough to use a few hours later without having had to clean and dry it after every application).

Didn't get on very well with applying by cloth, so went bck to brushing. Tried being very liberal with the shellac, and then putting it on more thickly, the latter strangely works better than I'd expected (pure luck maybe).

Overall in the shellac vs lacquer debate - I'd rather use shellac for fiddly pieces where a spray gun would be tricky but for large flt surfaces then spraying lacquer is evidently much less work. I'll post some pictures up when I've finished my experimentation.

 

[Newbie_Neil]

If you intend to brush Shellac on your projects it really is worth buying a good quality brush. They last years if not decades.

Not cheap, but definitely the right thing to do as it is the proper "tool" for the job and it will last years.

Thanks,
Neil

 

[Matt@]

Not my experience at all and I've done a lot of Spirit varnishing. All you really need is a jar of spirit that you use to soften the brush. Doesn't matter if it gets contaminated with Shellac, it will still be a very dilute solution. Just suspend it for an hour or so and it should be soft enough to use. I haven't washed a spirit brush out in years!

I stand corrected! a brush you are using on a regular basis with thinned shellac will soften quickly in either shellac or meths. A brush that has hardened, over time, neat shellac on it will take much longer and that was the one I was referring to in my post.....