WEEK COMMENCING 27 FEBRUARY 2022
Terry has made that fateful judgement and gone off on his holidays. Oh dear, that means you have me again with ramblings from the factory floor.
Orders continue apace, and the problems we were having with freight into Europe seem to have abated. Domestic deliveries are working well, but do let us know if there are any problems with receiving your orders. What happens once the packages leave the warehouse is out of our control, but I am always more than happy to have a moan on your behalf!
Anyway, enough of all that. No questions and answers this week, just some thoughts on the subject of compatibility. There is much to cover, and I will only be brushing the surface of it. I will be spreading my thoughts over the next 2 weeks (if Terry will let me!)
What we will discuss here is best practice. I may say something doesn’t work with something else and you may think that absolutely it does. If it does work for you then great, but it will always be that most special of pieces you have made where it goes wrong….S**S LAW!
Let’s start with Spirit Stains. To colour the wood, they need to be absorbed by it and therefore sealing is a no no, or very nearly a no no. If you have an open grain or softwood, you may find that after staining you have a blotchy appearance. This is caused by the stain being drawn in at different rates over the surface. A Cellulose Sanding Sealer, diluted 50/50 with Cellulose Thinners will be absorbed and dry just below the surface of the timber preventing the stain from being drawn in too far. This is the only time we would recommend sealing prior to staining. Spirit Stains are very versatile, and will allow you to seal and finish with just about any finish in our range – oils, waxes and lacquers.
Oils also need bare wood when being applied so no sealer should be used. They can be used over stains because the stain doesn’t form a barrier on the surface of the wood – it merely colours the fibres of the timber. Once a first coat is applied the stain will be locked in, and additional coats will not affect the staining. I should say here that if timber is stained, then too much mechanical action (brushing, wiping etc) on the first coat may lift some stain, but this should stop after the first coat has dried. If using Oils, then you should always stick with Oil or Wax, and preferably with the same oil, and if you move onto Wax, you shouldn’t go back to Oil, only more wax!
Food Safe Products should only be used with other food safe products. If used with anything else the product ceases to be Food Safe. You cannot guarantee that, for example, solvents used in our Finishing Oil wouldn’t leach into Food Safe Finish or Microcrystalline Wax. So, if your item needs to be safe for food contact, then only use our Food Safe Finish or Microcrystalline Wax.
Something that took me a while to get my head around was the compatibility, or not, of Acrylic and Cellulose finishes. I couldn’t understand why you could put an Acrylic Lacquer over a Cellulose Sanding Sealer, but not Melamine over Acrylic Sanding Sealer. I got there in the end! The solvent in Melamine is very aggressive and, if used over Acrylic, Oil or Wax, could lead to the first coat ‘pickling’ or blistering. The cellulose is attacking the previous coat. If sealing timber, it would seem to me that the best sealer to use (which would be borne out by the quantity we sell), is the Cellulose Sanding Sealer. Once dry, apart from Oils, you can finish with just about anything – Acrylic, Cellulose, Friction Polish or Wax.
If using the Acrylic Sanding Sealer, the finish can be Acrylic or wax, or indeed our French or Friction Polish. With both of these sealers, you can also apply the Iridescent or Metallic paints, or our Rainbow Waxes on top. If you have painted or Rainbow waxed the bare timber though, you are then limited to the Acrylic Sanding Sealer. A bit more limiting, but a more traditional approach to finishing, is using the Shellac Sanding Sealer. It can be used over the Spirit Stains, but again care would be needed. As they share a common solvent, it will lift the stain. Traditionally, you would then finish with the French Polish, Friction Polish or waxes.
You should also try to avoid using a harder finish over a softer finish. I know that people do, and swear by doing so, but there is always the risk that a hard finish (say, a Lacquer or a Sanding Sealer) will crack, or craze, if used over a wax (say Gilt Cream or Rainbow Wax used to pick out the grain on an Ebonised piece of work). Best option is always to go softer. It is good to point out here that a harder wearing finish is not the same as a harder finish. So you can safely apply the Microcrystalline Wax over the Woodwax 22 because it is still a wax. The difference between the two is that the particles in the Microcrystalline knit tighter together as it dries forming the harder wearing finish, but the coating itself is still as flexible.
There you go for part 1. Hopefully Terry will have enjoyed a good week off and will let me loose on the keyboard next week. If not, you may have a long wait to hear the rest of my ramblings! Hope you all enjoy a good weekend, and either Terry or I will see you back here next week.