Why oil French Polishing pad?

[ubeaut]

Sorry took 20 minutes to edit it with some pics etc.

[Dengue]

I put about 5 coats of shellac on a timber case which had one vertical side open. This was done 2 days ago, allowing about 10 minutes between coats.
Today I picked up this case, fingers underneath, thumb on top side, and found my thumb left a smudge. Can anyone pleasse tell me why this happened and how to avoid it in future?

It is 30-32 degC during the day here, and the humidity is 90% at night and in the early hours of the morning, dropping to a minimum of 65% during the day, on average here in Townsville at the moment.

The good news is that I very lightly sanded the top with 400 grit and wiped the nearly dry rubber / pad over the top and the smudge appears to have gone.

So much to learn with shellacing

Just opening Neil’s “ A polishers handbook” 4th edition. I would not have read this manual for over 10 years

[yvan]

I had the opportunity to practice applying shellac with a brush on plywood I later used to make some shelving. I used a 2lb button shellac cut: diluted back 50:50 with metho for coat #1, 75:25 for coat #2 then full strength for #3 and a 2". It was applied with a cheaper synthetic brush with light sanding in-between.

It certainly was an interesting exercise !! I made sure that the brush was used in one direction only to avoid going over the same area twice. I also found that by paying good attention to loading my brush consistently I would avoid getting a mix of wet & much drier streaks, particularly with the 1st coat. After reading UBeaut's advice, I am sure that using a quality brush will make all the difference.

I also tried as much as possible not to overlap the brush strokes as I could see that the layer of shellac was thicker where I had done so. This was the hardest. Instead of overlapping I would leave a "gap". Very obvious with the 1st coat but not so much with #2 & #3 coats !! So, I should perhaps continue the process by applying additional coats with a wad to blend the layers together?

I used button shellac because I quite like the tone but it is certainly not a clear brew. I suspect though that the particles in suspension would act as a filler.

Cheers Yvan

[homey]

Joe,

If the shellac was still soft after a couple of days my first question would be how old is the shellac? Once mixed shellac gets old it doesn’t dry properly. Neil’s product has a “use by” label and I go pretty much by that. Unfortunately I’ve no experience polishing in the temperature/humidity combination you get in Townsville - let’s hope Neil is still reading this thread

As to finishing inside the box, yes - more often than not I give the inside a coat (dewaxed). Mainly for cosmetic reasons but also I find that the double-sided tape I use with linings adheres better to the shellac than to bare timber.

Best regards,

Brian

[Dengue]

Ahhhh... never thought of that, Brian. The Ubeaut bottled white hard dewaxed shellac is 18 months out of date, could well be the problem

[homey]

That’ll do it every time

[ubeaut]

Ahhhh... never thought of that, Brian. The Ubeaut bottled white hard dewaxed shellac is 18 months out of date, could well be the problem

That will definitely be the problem without a doubt.

Had I been around earlier when you mentioned the thumb smudge the first thing I would have asked is how old is it.

I have heard of people using the Hard Shellac up to 2 and ven 3 years out of date and getting a good result. This could be more down to the hardener than the shellac. I most certainly wouldn't trust it at that age. Ideally you should use most shellac within 6 mths however we use a heavier concentration of shellac to metho which gives a longer life and usinf 100% ads more life as does the hardener, but after 18 months I wouldn't be using it.

After shellac expires it will appear to dry but won't fully harden. EG; finish on a table with out of date shellac (any sort) will appear to be dry and hard but put a pot plant on it for a few days and when you remove it there will be an impression of the bottom of the pot on the surface of the finish. Pit the pot plant on a doily and you will have a nice doily imprint left in the finish.

Sorry for the bad news.

[Dengue]

Many thanks for this valuable information, Neil. I have only just read last night in your Polishers Handbook about esterification where the alcohol adversely impacts on the shellac resin past its use by date. The beauty of a shellac finish is that I can wash it all off with metho and start again

I was telling my wife about how the shellac I was using was 18 months out of date and would not dry properly. She went to the fridge and bought out a cardboard box from deep inside it. On opening, it was 500 gm of fine white shellac powder in a vacuum sealed plastic bag. There was an invoice in there too, date Oct 2012. She had been storing this for 8 years. She told me I had asked her to keep it cool when I first bought it as it was very expensive. She said she had asked over the years if I still wanted it stored. Puts up with a lot, does my wife, but is totally supportive of my woodwork hobby. It was not long after 2012 that I gave shellac away, not having any success with it on my boxes. I was using a very fine brush, and I was hopeless at it.

I dissolved 24 gm of this powder in 100ml of Diggers 95% metho last night in a tall plastic sealed container, and within 5 minutes it was totally dissolved. There appeared to have waxy deposits on the sides of the container. Will let it dissolve for another day, and then try it out on some fine sanded timber to see if it drys OK

At this stage I doubt if I will need to buy any white dewaxed shellac powder for a while, which I have now stored in a sealed plastic jar back in the fridge

[Dengue]

When I first start polishing a box with shellac and a rubber on a box surface sanded to 600 grit, I put down three runs side by side, slightly overlapping. When I then go to start rubbing all over the box surface in various patterns, like in the videos mentioned above, the first run becomes tacky straight away.

What am I doing wrong?

[homey]

Hi Joe,

If it is only the first pass that is getting sticky I’d guess that there was too much shellac on the rubber.
I’m no expert, but these guidelines work for me:

* Rubber made from worn cotton or linen
* A thin ‘cut’ of shellac. In the case of Hard Shellac I thin the bottled product to 50/50.
* Old mixed shellac is a nightmare. Fresh shellac is a dream.
* Only ever a moist rubber, never wet. Blot on a piece of white copy paper until any shiny wetness is gone.
* Keep the rubber moving - never stop on the surface. Glide on, glide off.
* Don’t move slowly - it increases the likelihood of sticking.
* A small amount of mineral oil on the outside of the rubber - just enough to prevent the rubber from sticking.
* Look for the vapour trail behind the rubber.
* At the first sign of the work becoming sticky walk away until it has had plenty of time to dry.
* In my case I prefer to add shellac by opening the back of the rubber - just personal preference.

Polishing is a bit like learning to drive. At first it seems impossible to steer, indicate, change gear, manipulate three foot pedals. Amazing how quickly it comes together, though.

Best regards,

Brian

[Dengue]

Thanks Brian. Yes, I thought the wetter the rubber the better, being nice to see that thin run of wet shellac on the timber. Big mistake. Back to the practice board for me

[woodPixel]

Stupid question, but if I have unused dry shellac still in the bottle, sealed well, is it still usable even if a few years old?

[Dengue]

Hi woodPixel, not a stupid question, and a very important one. Were the shellac flakes kept in a cool location, like in a fridge?

Extract from Neil's "A Polisher's Handbook" 4th Edition : Flake Shellac has virtually unlimited shelf life if kept dry and out of direct sunlight.... To determine if your shellac is good, put some in metho, and if it not dissolved within a couple of days, CHUCK it out"

[auscab]

When I first start polishing a box with shellac and a rubber on a box surface sanded to 600 grit, I put down three runs side by side, slightly overlapping. When I then go to start rubbing all over the box surface in various patterns, like in the videos mentioned above, the first run becomes tacky straight away.

What am I doing wrong?

Well your doing one thing right Dengue . You keep trying and asking .
At some point it will get better . I wish I could give you a few ten minute in workshop lessons .
Id enjoy seeing the penny drop .

One thing to remember with FP is what ever you do in the first two sessions, it hardly shows . If they are done right you will just see progress at the end of the second session but its the third session that really is rewarding . And from then on it gets even better . Nothing really shows in the first session if you just keep going at it apart from " Ive gone to far and what I put on is coming off !"

First session your laying down a foundation to work on, so wipe on as many straight coats as you can , and practice wiping them around in circles and figure eights to the point of it almost coming off , let it sit a few minutes and lightly, with a wet rubber rub it straight and then leave it a day . It should be sticky enough for a fly to get stuck if you get good at it .

Next day get some fine worn 320 or 400 grit paper and give it a cut back with a linseed oil / mineral turps soloution 70 / 30 mix. Cut it back as hard as you can without hitting raw wood . It wont take much, no problem if you do but practice counting how many circles it takes to go through and then stop before that .

Now do the second session same as the first , lay it on straight so you get evaporating trails but building layers and then go into circles and 8s again as much as you can but really pay attention to not wiping off yesterdays first session . It'll be getting sticky too. If your doing well at the end of this like I said you may just start to see the grain starting to fill . Depending on the wood type as well . Let it dry a day .

Now the third session, starting with an Oil and turps cut back again, will start to look better with the cut back and the session or the body of shellac you are giving it after the cut back will be the first time you see things changing in a big way . You probably wont get total full grain but it will be well on its way . Knowing when to stop trying is a feel thing through these sessions and doing it wrong will teach you . Its easy to burn through if trying to do too much at once .

The shellac mix can be pretty thick with the bodying sessions but watch how thick shellac behaves and leaves tracks like grooves on a record . It doesn't matter when bodying because the oil and turps cut backs flatten it off later and its all about filling the grain . But after your happy with the grain fill and going into finishing sessions , session 5 say, after the carefull cut back the shellac must be thinned quite a bit .

You can take it down in stages but the final sessions are real thin .

Thin shellac may take longer to lay slightly but finishes a lot finer and beautifully using oil . Ive always stuck to Linseed oil for this . Will try some paraffin one day . I once used Olive oil just as an experiment . It seemed to work ok .
The art of using Oil for finishing off and really thin shellac at the end gives great results . I'm talking thin like a coffee mug full of metho with an egg cup full of shellac mix as I remember the way the u-beaut bottle I had a while back came . Its a pretty thick good value for money mix . I just tested a coffee mug with an egg cup . 8 shots of metho to one shellac would have it over flowing .
When you mix shellac like this or thicker try wiping a well squeezed rubber over the back of your hand and blow on it to feel the metho evaporate then feel with your lips how tacky it is . That'll show you how much shellac is there and that your actually leaving shellac on the job .

When bodying in the first few sessions you need to control how much is leaving the rubber by squeezing it . If your leaving wet trails on the job , rooster trails I call them, like Motor bike riding in dirt does . Your not getting anywhere good with that . So figure that out . You can lay on a lot with each circle in early sessions but no Rooter tails . The wetness can be used as a lubrication on the sticky sessions when you get skilled enough . As you get to finishing session stages though you must squeeze that rubber real dry after its dipped for a re fill . Its got to be a wet rubber but only just coming out with a wipe on the job , or on the back of your hand . I squeeze down a newly re filled rubber til no drops can be had from it .

Hope That's a bit of help to you .
Ill probably re read for mistakes and edit them a little later. There's got to be some in that .
Rob .

[ubeaut]

To determine if your shellac is good, put some in metho, and if it not dissolved within a couple of days, check it out"

If after dissolving it looks like mushy cornflakes... Throw it out.

If it hasn't started to dissolve within a few hours chances are it's not going to be too good as shellac. But if it does mostly break down over the next day you can strain off any rubbish and it can be used as a knot and sap sealer. If it doesn't work for that..... chuck it.

1. If it's white or dewaxed white shellac hasn't been refrigerated at all and has been through even a few really hot days it's a 95% bet it won't be any good as shellac. One reason to only buy it from someone who keeps it refrigerated and not on the shelf. I wouldn't buy it off the shelf.
2. If it's white or dewaxed white shellac and after mixing there are fine sandy looking solids in the shellac then it has at some stage been heat affected and may not work properly as a portion of the shellac is mot mixed in and never will.

Both # 1 & 2 above can be mixed down with 10 parts metho and used as sanding sealer, although that works better with dewaxed shellac.

I have seen videos about white shellac where they say you have to filter off the solids after you make it. This is part of the process. NO IT'S NOT! It means you've been sold poorly stored shellac that's been heat affected and will not work to it's full potential. That's one reason to buy good quality white premixed and with a best by date clearly on the container.

FINAL TIP. Never buy shellac in a tin, never store shellac in a tin, never pour shellac of any sort into a tin for storage. Shellac and tin don't like each other. Tin (any metal) will turn shellac black and make it all but useless. Shellac is an oxidising agent and will rust metal overnight if it's in contact with liquid shellac.

Thanks Brian. Yes, I thought the wetter the rubber the better, being nice to see that thin run of wet shellac on the timber.

Did you have a look at the video link I put on in earlier post How to French Polish - Woodworking Finish with Shellac - YouTube if so you would have seen how dry the first applications were.