I don't know if your artist colors are light fast or will fade under intense sunlight. I do know there are exterior grade water based dyes. These can handle the sun. Look for them online. Then I would apply a spar varnish of your choice.
I have a 2 part question:
Thanks for any insight provided.
1. I want to re-stain a hot tub/spa that gets 5-6 hrs of direct sun per day. I want a "Jacobean" like brown/black I can't find in a traditional "Olympic" style deck exterior stain, so want to use interior furniture grade oil stain. Will it work? Stain is stain, right? Maybe follow with a couple coats of Tung oil to protect it. Tung being more water resistant than linseed. The original factory finish only lasted a year anyway, so can't be much worse than that. The reason it's marked interior stain is the pigments are not suited for exposure to sun so stain is not stain. It would be better to use a exterior deck stain or thin a exterior oil based enamel for the color. Jacobean shouldn't be a hard color. It's mostly black. It's when you start staining with the color red it gets hard as red is bad to fade.
2. I plan to experiment making my own oil stain (see below*). I have a set of oil paints that are 60 yrs old. The tubes of the colors I need are still squishy and soft. Will they still work? I don't think I would use 60 year old paint for any important project and artist oil is also a interior enamel which shouldn't be used. The paint is likely to contain lead for one and it may be so old it creates adhesion problems. There would be no way to find out except to use it.
It would be difficult to say about the formula if you intend to use it. I would mix the brew without the mineral spirits and add that last as needed. If you get it too thin to begin with you would have to add a great deal of the other components to thicken it.
Another thing that would help stained wood in the sun is a product called Sun Block. It is sold by Kwick Kleen. It's kind of like sun screen made for wood. You would use that first and finish over it. A marine grade spar varnish would also give you better UV protection.
Are you pulling up old threads just to post that same link. Appears like spam to me.My wife and I recently completed the staining of our family's backyard deck as a DIY project and I'm very pleased with the results! I purchased an exterior stain from Storm System and they have a variety of colors and levels of stains available. You should look into their offerings and see if they are comparable to your vision for your goal of the wood's color.