Jump to content

Recommended Posts

Hi All

 

I've just discovered this french polish at my local hardware store and thought I'd give it a go:

 

5a76f6e022362_FrenchPolish.thumb.jpg.3c9d24934383c3aca312837bb001b351.jpg

I tried it neat on bare wood, and over matt varnish. In both cases it gave a beautiful silky smooth finish, although the effect was more subtle and effective when used neat, at least to my eye. Over boxwood, it seemed to impart a warm glow to the timber (beyond the capacity of my ancient iphone camera to capture adequately, I'm afraid ).

 

My question is, before I use it in earnest on a model, is there anything I need to be aware of? For example will the french polish finish stay looking as good as it does now, or will it fade or discolour over time? Should I apply any sort of topcoat? I'd always thought french polish was a top coat, but if it needs periodic reapplication or touching up then it's not much use on models. I'd be grateful for any thoughts and experiences other folks might have.

 

Thanks

 

Derek

Link to comment
Share on other sites

Strictly speaking 'french polishing' is a technique for applying shellac based finish to wood which involved a pad of cloth saturated in the shellac solution.

A great deal of antique furniture was finished with shellac rather than varnish, originally varnishes being made from turpentine and amber.

Shellac is a naturally occurring plastic that dissolves in methanol - the solvent used is methylated spirits, so use in a well ventilated area - and because it is solvent based when a new layer is added it partially dissolves the previous coat and flows into it - so that there is not really one layer upon another, if you see what I mean. I can attest to its finish being superb, I've used it on a mahogany guitar and a number of other things. The guitar was finished with grain filler to stop the finish sinking into the end grain, then sanding sealer (which was another shellac solution with ground up pumice as a very fine filler) That was flatted of with 1000 grade wet and dry and then a couple layers of final shellac/french polish. The result was like glass. I have always applied the finish with a brush, never actually the proper french polishing technique.

Also, shellac is know to be neutral with most other finishes, it doesn't react with them and craze for example, hence why it is used for sanding sealers.

 

Edited by FatFingers
Link to comment
Share on other sites

Thanks for the replies guys. The instructions on the bottle say it should be applied with a polishing cloth like Jim says. However I used a brush like Fatfingers and found it went on fine. Just one coat gave the lovely subtle effect I described (on well prepared, smooth boxwood). I suspect more coats would produce too glossy an effect for a period model. 

 

I’m particularly interested to hear that french polish is neutral. I’m still worried that the bare polish might not last over time, so I might experiment with various topcoats (matt acrylic varnish perhaps?) to see if I can protect it without losing the effect. 

 

Thanks again for for the very informative and useful replies. 

 

Derek

Link to comment
Share on other sites

Agree, shellac can be applied with a brush in multiple layers to build a magnificent deep finish on models.  Applying with a pad works better for large surface areas as in furniture. Available in various tones including a clear version known as white shellac. The finish is very durable and long lasting but easily scratched. But then again is very easy to repair. On static models potential damage should not be a problem. Be aware that glueing wood over shellac coated wood does not stick very well. The bond will eventually fail.

Edited by Chooflaki
Link to comment
Share on other sites

I think shellac is not waterproof so does not seal the wood well. Also I think it has a shelf life. I used it in the past but I liked pure tung oil better which gives a warm tone to the wood, shellac needed too many coats. Also, I find water based sanding sealer excellent and now use it a lot. It pretty much does the same as shellac. It is colourless but it can go on top of tung oil, using the oil diluted and allowing time to cure. It leaves the wood smooth and shiny.

 

Link to comment
Share on other sites

Oops! Just seen your reply vaddoc so now I’m I two minds again. I think more experimentation may be the order of the day. I’ll certainly try tung oil and sanding sealer as you suggest. I  suspect I may struggle with the latter. I’ve got spirit based sanding sealer, but the only water-based product I can find (at least on a quick Google search) is ridiculously expensive. I’ll keep looking. Thanks again for your information and advice. 

 

Derek

Link to comment
Share on other sites

Derek, this has been just my experience though, maybe you ll fair differently! I ve spent a very long time experimenting though with finishes (in scrap wood, not the boat!).

I ve come across this sealer in the past

 

https://www.amazon.com/DecoArt-DS17-9-Americana-Multi-Purpose-8-Ounce/dp/B000YQJQ82/ref=sr_1_1?ie=UTF8&qid=1517916231&sr=8-1&keywords=americana+sealer

 

It can be found in the UK for £2 a small bottle which goes a very long way and does a brilliant job, dilutes with water and dries in 15 min. My hull has only this sanding sealer on for now (2 coats) and is sanded to 0000 steel wool. It is very smooth and reflects light

 

20180107_161609.thumb.jpg.61ae54814cd4020469d0ebd94c7b26cd.jpg

 

regards

vaddoc

Link to comment
Share on other sites

If you want to have that deep, shiny, polished look, then shellac applied as French Polish is the thing to go for. Have done quite a few squaremetres in that way. In Germany we have the Clou product range, which is excellent. Not sure whether they export to other countries, as the French do with their expensive 'Luberon' range. The Clou sanding filler is actually a filled nitrocellulose lacquer, not in the resinous excretions of Kerria lacca (a kind of plant-living louse) dissolved in alcohol, i.e. shellac.

 

On furniture surfaces I apply shellac with a bud, a piece of discarded (washed!) cotton underwear that is stuffed with cotton wool. When applying the actual final polish, you put stroke next to stroke with the saturated bud, and fast. Otherwise, you will get streaks and the bud will stick, destroying your previously built-up polish.

 

Before commercial sanding sealer became available, the cabinet makers spread pumice powder on the wood and rubbed this in with shellac. The pumic acted as both, as sanding compound and filler. After this the actual shellac polish was applied.

 

Cabinet makers, or rather the polishers, who were as special trade, made their own shellac polish from shellac and alcohol - which is why many of them seem to have been alcoholics - because in between they took a sip from the bottle (without shellac). Some of them also became blind, because of the impure ethanol that was used.

 

For small parts, where you can't apply the polish in the usual way, I apply the shellac by brush and when dry, I rub it down with pumice powder that I pick up with a moist finger or cotton-stick. This removes all brush-strokes and thins down the layer. If it has to be shiny, I then burnish the surface with a dry cotton-stick.

 

BTW, the above Clou sanding sealer in itself makes a good surface treatment, particularly for harder woods. I apply it with a brush and then rub it down with steel-wool. Gives a nice smooth satin finish, which is hard-wearing. I treated the beech work-surfaces on which my machines are set up in this way - but not my work-table, because there I may be handling with solvents that could mess up the table.

 

Edited by wefalck
Link to comment
Share on other sites

Hi wefalck, and many thanks for a most informative post. It amazes me how much knowledge there is on this site - I particularly enjoyed the snippet about polishers and their foibles. I do like a deep shiny look, but on furniture and musical instruments, not ship models, where I prefer a more subtle look. I like the sound of the Clou sealer and will try to obtain some to add to my list of finishes to experiment with.

 

 

Link to comment
Share on other sites

I had to google pumice powder, never heard of it!

 

"Pumice powder is made from pumice, a kind of igneous rock that is formed when a volcano erupts. Pumice is abrasive, which is where much of pumice powder's usefulness comes from."

 

Another thing, Liberon shellac is not dewaxed. It is not a big deal as the wax settles in the bottom if you leave the container still for a few days, then the pure shellac can be drawn from above.

 

Vaddoc

Link to comment
Share on other sites

My mother used to keep a pumice stone in the bathroom to rub the hard skin off our feet, but I'd never associated it with ship modelling!

 

I hadn't realised that Liberon has wax in it. I had noticed that something milky had settled to the bottom of the bottle before I used it and I stirred it in. Perhaps that contributed to the silky finish?

 

Derek  

Link to comment
Share on other sites

Well, as a geologist it would rather say: pumice is formed when a gas-rich lava is cooled down rapidly, so that the gas-bubbles that form, when the lava rises in the vulcano, cannot escape. Rapid cooling happens, for instance, when the lava erupts below sea-level or runs into the sea. The specific density is less than 1 g per cubic centimetre, so that pumice floats. Classical places for this in Europe are the Stromboli in Italy or the Greek volcanic island Santorini. Ladies are probably more familiar with the material, as it is used in form of little block to smooth heels.

 

I found that with the pumice method one can quite well with the shine and the depth of the lustre. Difficult to photograph, but this is an example of a mahogany companion-way (1:60 scale) I did some 30 years ago:

 

http://www.maritima-et-mechanika.org/maritime/models/steinhaus/steinhaus-28-72.jpg

Edited by wefalck
Link to comment
Share on other sites

  • 6 months later...
On ‎2‎/‎6‎/‎2018 at 2:33 AM, vaddoc said:

I think shellac is not waterproof so does not seal the wood well. Also I think it has a shelf life. I used it in the past but I liked pure tung oil better which gives a warm tone to the wood, shellac needed too many coats. Also, I find water based sanding sealer excellent and now use it a lot. It pretty much does the same as shellac. It is colourless but it can go on top of tung oil, using the oil diluted and allowing time to cure. It leaves the wood smooth and shiny.

 

Shellac is about as close to "waterproof" as any finish coating can get. It is sometimes used in full-sized yacht construction as a sealer beneath finish coats of varnish or paint. I apply a liberal coating of shellac to wood on models, particularly solid hulls. It is a good sealer, fine sands easily, and stabilizes the wood, minimizing movement with changes in ambient humidity. As noted by others, it also adequately mimics a varnished brightwork finish on models.

 

Tung oil will take a considerable time to cure unless thinners (for brushing conditioning) and driers (to speed drying) are added, in which case, it becomes varnish. Unlike "spar" varnishes, however, it does not contain UV inhibitors and will degrade in sunlight.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...