Drying time of French Polished

[sihollies]

Hi
Hi

Could anyone please advise me as to how long it should take for French Polish to dry fully?

I am trying to teach myself how to French Polish.

I completed a sample piece of cherry to an extremely satisfying finish and kept it in a warm dry atmosphere.for 5 days to dry, and on doing so it appeared ok

A friend wanted to see the sample, so I took it round in a cardboard envelope, with solid sides.

When I took it out of the box, there were several small marks all over the piece of cherry. I can only assume that I didnt leave it long enough to dry out, or could I have possibly not have applied the shellac properly?

I am new to French Polishing, so any advice is welcome.

Thanks

Simon

 

[Gary Morris]

On my 'Colron' French Polish it's 24hrs to dry. Did you mix it yourself? I read that you can add Boiled Linseed oil which extends the drying time. I got my info from here http://stores.ebay.co.uk/endlessgreengroupltd

Gary

 

[sihollies]

Thanks for the reply Gary

I did mix the polish myself, but am now trying another board with ready mixed polish.

I applied the shellac with a rubber in long straight layers. As recommended by someone, I also added a little boiled linseed oil to the 2lb mix to prevent dragging. I applied many dozens of layers over several days.

I then used a 1lb cut with no BLO along with neat meths until i achieved a streak free surface.

The rubber didnt drag on many occasions,as the sample board is only quite small (approx 300mmx200mm), and I was only laying down one layer and then letting it dry for 10 mins or so.
Simon

 

[marcros]

IIRC, it can take weeks to fully harden. The drying is probably more a minimum overcoat time.

 

[sihollies]

Hi

I have just had a thought.

My final process was to apply a 1lb cut of shellac with additionl meths applied to the rubber. Could it be that i have applied lots of very fine layers of shellac that are just 'sitting on top' of each other, and thus creating several fragile layers ??

Like I stated, I am new to this and it is just a theory.

I have just cut it back using just meths, so will let you know how I get on.

Simon

 

[MIGNAL]

You don't really get layers with French Polish. 5 days isn't long enough for the Shellac to fully harden. I leave it 3 or 4 weeks minimum.

 

[sihollies]

Thanks Mignal
I will leave it for a month or 2 to harden, and will post what the outcome is

Thanks again

Si

 

[Muswell]

Hi Si, it's me again

Maybe you built up the thickness too quickly. For guitars I have built up the finish in 5 or 6 sessions leaving 2or 3 days beween. After the final session I left it for a week. I thought you weren't supposed to put oil in the mix. I have just put a drop of olive oil on the rubber when necessary.

You might find this helpful http://milburnguitars.com/frenchpolish.html

It might seem a bit elaborate but guitars are expected to be of a very high standard.

John

 

[sihollies]

Hi John
Thanks for all your advice. !!
I think I did build up the thickness too quickly. On a new sample I gave the surface 4 sessions then left it over night to 48 hours before I repeated.
I then left it a few days to finish it off. The result is pretty good.
As stated, I am new to French polishing, and I was advised on this forum to add BLO to the mix, ( unless I misunderstood the post?), and was/am happy to accept any advice.
If I have indeed layed on the shellac too thick; do you think the polish will dry eventually or is my sample just a failure

Many thanks again

Si

 

[Muswell]

With both oil varnish and French Polish you need to build up in thin layers with plenty of time between. You can't go wrong by waiting too long but if you build up too fast the lower layers are still soft and you can get long term problems ( voice of experience) I don't think your sample will be a failure, but rather a useful learning experience on whether that was too thick.Try to read the link I sent you, it's good.

John

 

[Matt@]

in french polishing something and packing it after 5 days, I would not expect to see any marks to the finish unless it had been pressed hard against a blanket etc. When I say hard, I mean placing a blanket over the top of a french polished table top and sitting a chest of drawers on top of it!.

packaging up an item that has been french polished would not in itself IMO mark the finish. Its heavy pressure bearing down that cause the problems...

Use of oil and age of polish influences alot of the above...

 

[sihollies]

Thanks very much!!!,
I think I have stated before that I considered that finishing a project was a trivial after thought ( i,e. sealing and waxing ).
But realise how naive I have been.
In perspective: I mainly make parquetry boxes which may take 3-4 months to produce, and until very recently, just gave them a coat of wax.
I spend a huge amount of time constructing the item, and don't feel 'a lick of wax' shows any respect. Thus, I want to experiment with the multitude of finishing techniques available, so I can incorporate them into my projects

Si

 

[mrpercysnodgrass]

Si,
I have been french polishing professionally for 32 years and I have never heard of anyone adding boiled linseed oil to shellac. This is where your problem lies. Throw away this mix you have made, it will never give you a good finish.
Other than adding the oil to your shellac you have not done anything wrong, so if I were you I would strip off the finish you have applied and start again.
You can use raw linseed oil to assist in polishing, first get a good skin of shellac on then take one small dab of raw linseed oil with your finger tip smear this on you pallet and work your rubber over this, you can then apply the shellac to your box, when you have built up your polish stop using the oil and finish with a clean cloth over your fad or use a new rubber.
As matt@ said, use of oil and age of polish will influence the hardness of your polish, if your polish is more than six years old it will not harden, ( it goes through a process called esterification ) it is always best to buy small fresh quantities of shellac. Also some shellacs are harder than others the three softest are white polish, garnet and button. The best all round shellac is special pale. You can get a variety of modified shellacs which will be harder, one of my favourites is Jenkins pale outside polish but you cannot use oil with it.
If you re-polish your box, it should be hard enough to wrap and transport after three or four days but will not fully cure for about four weeks.

 

[sihollies]

Thankyou for your advice / knowledge
I have already binned the polish with the added oil, and attempted another sample piece using ready made 'special pale shellac' from
Priory polishes ( via Ebay ), and all appears well at the moment.
As stated in one of my initial posts, I am just starting on the French Polishing journey, and have only attempted sample pieces, and dont intend to try it on a finished item until I gain a bit of confidence. But hopefully that will be in the near fuure.

Thankyou all again for your input

Simon