Re: Shellac degrading in the bottle / good finishes

[nicguthrie]

OK, maybe I should have added this to the bottom of my last post, but I thought that it's a slight change of topic, and may be useful to others in searches in future as a separate topic.

I was warned both in this forum and in a book recently that Shellac polishes can degrade badly over time in the bottle if they're not used in fairly short order. I was wondering if this also applies to things like shellac based sanding sealer? I'll be buying some various finishes soon with a bit of a spending splurge as I am just setting up and have none, and I'd like to know which things to stick to getting very small amounts of, or indeed missing altogether until I know I'm about to use them.

I'm learning like mad (indeed, I probably am rather mad) but I'm pretty convinced that the finish is probably the most important part of any woodworking project, and I love to really bring out the beauty of wood, even if it's just a quick wipe of meths or water, to view the depth of colour and grain hidden in the wood.

If you have any recommendations for particularly easy or gorgeous finishes either on a lathe or on hand made work, I'd appreciate any personal favourites that you'd like to throw my way too, either in pm or here.

Thanks folks, this really is a pretty awesome community.

Nic.

 

[Peter Sefton]

Stock rotation and shelf life is important in glues and finishes, here are a couple of finishes we use in the workshop
http://www.agwoodcare.co.uk/Item/blanch ... nvironment
http://www.agwoodcare.co.uk/Item/blanchon_hardwax_oil

Both are easy to use and give a good finish.

 

[Woodfinish Man]

This issue seems to becoming more prevalent in recent years and I can only put it down to one thing, many shellac based solutions that are on the market are being made using cheaper synthetic shellac rather than pure shellac. This is being done as the price of natural shellac has gone up by nearly 200% since 2009!

I have heard many stories of customers saying that they are using shellacs that they've had for 5 , 10 and in some cases 20 years! The only issues these customers have found is the shellac taking slightly longer to dry and this can be combated by adding a drop of meths.

We officially give our shellac polishes a shelf life of a year but as I've said this is a bit like the 'best before' date you find on tins of soup!

Hope this helps.

 

[MIGNAL]

Nothing to do with synthetic Shellacs. It happens to the best pure grades as well. Technically I think they call it esterification. Mixing a thicker cut (less alcohol) seems to help it's shelf life. Dilute when needed. Storing it in sealed, full containers (away from light) and cool might also extend it's shelf life. Waxy Shellacs certainly lasts a lot longer in it's dry form (than non waxy Shellacs). Not sure if that's the case when mixed though.

 

[nicguthrie]

Thanks for all the advice. I'll be buying some soon, and I think I'll get myself a small bottle of a shellac based finish, like a rustins or another big brand - as I'm curious as to the benefits of these types of mixtures that all mention being based on shellac and resins etc. But I'll also buy a quantity of "real" shellac and mix some up for myself.

In the book I have on finishes there's a great article on a super quick version of a shellac finish, using a boiled linseed oil wipe finish, followed by a dilute cut of shellac in isopropyl alcohol. I plan on giving it a shot, as it sounds ideal for lathe work and small stuff like what I am specialising in.

I'll look forward to some experimenting. Only one thing to figure out now, and that's the difference between the dewaxed shellacs, and the different colours and types of shellac flakes etc.

Thanks again guys.

Nic.

 

[marcros]

Thanks for all the advice. I'll be buying some soon, and I think I'll get myself a small bottle of a shellac based finish, like a rustins or another big brand - as I'm curious as to the benefits of these types of mixtures that all mention being based on shellac and resins etc. But I'll also buy a quantity of "real" shellac and mix some up for myself.

In the book I have on finishes there's a great article on a super quick version of a shellac finish, using a boiled linseed oil wipe finish, followed by a dilute cut of shellac in isopropyl alcohol. I plan on giving it a shot, as it sounds ideal for lathe work and small stuff like what I am specialising in.

I'll look forward to some experimenting. Only one thing to figure out now, and that's the difference between the dewaxed shellacs, and the different colours and types of shellac flakes etc.

Thanks again guys.

Nic.

I would wholeheartedly recommend Smith and Rodger for your shellacs. They manufacture so the stock will be fresh, and as Woodfinishman has demonstrated, they know their stuff.

The different colours of shellac is down to the refinement I believe, with the superblondes and pale ones being more refined than the garnets. There doesnt appear to be a standardisation of colour, so some brands call them different things, particularly in the paler shades. If you are a small user, then you could (I would think) get one of the paler shades, and tint it to your requirements. I have some transtint dies that will do it, but I am sure that there are some that are more easily available (good though they are).