I'm going to be treating beechwood counter tops with linseed oil (following these instructions).
The person in control of the budget has asked me to figure out how much oil will be required (so we don't buy too much).
The tops are 40mm deep.
How many ml of oil should be used to give a single coat to a 1000mm × 1000mm × 40mm block of beechwood?
I am assuming it will be the same amount for each coat, so let me know if that assumption is wrong.
Is there a heuristic I can use to work it out for other thicknesses?
Given that, I can figure out the total required from the number of coats and reapplications.
Best Answer
The oil that you use (or are thinking of buying) will typically list the coverage on the package or instructions as BMitch suggested in the comments.
For instance, on the website you linked to for the instructions, they sell this (randomly chosen by me, no endorsement) counter top oil, and in the description it says:
So this 500ml can will cover 6.5 square meters, or give your 1 square meter surface about 3 coats. You mention the depth of the counter top, but that shouldn't matter. The oil is largely a surface treatment, and the coverage will not change based on the thickness of the wood.
It's been my experience that the first coat might "soak in" more than the additional coats, so the coverage won't be as high as advertised. In the case of this oil, I would worry that a 250ml can wouldn't be quite enough, so I'd get a 500ml and feel good about having some extra for later.
Of course, look at the coverage on the oil that you want to buy and do the calculations for yourself.