Prepping End Grain for Finishing to Prevent Too-Dark Results
There's more than one way to condition end grain so it won't soak up too much finish and look different when compared to the rest of the piece. November 15, 2010
Question
I have a customer who is complaining that she does not like how dark the end grain gets from the stain. I told her that it’s just the nature of wood but wanted to do some research as I'm new to finishing my own work. So the question is, is there a way to keep end grain from getting so dark during the staining process?
Forum Responses
(Cabinetmaking Forum)
From contributor L:
You need to get some books on finishing. It's called a washcoat and can be as simple as mixing PVA adhesive with water 1/10 and applying it and sanding as you normally would. You can also cut shellac and do the same thing. You can buy products to do the same thing but I prefer to use a stock item for this. Properly done the end grain will stain like long grain. This is an old technique. Learning how to search here and with Google will help a lot but you should get Flexners book and other books on finishing. Books will never go out of style.
From contributor F:
Your customer is right. You need to do a little more homework before blaming the "nature of the wood". Properly stained the end grain should not be much, if any, darker than the rest of the piece.
There are several ways to deal with this problem and you'll need to do some practicing to get it right. I usually use a pre-stain conditioner to allow the end grain to partially seal before applying color. I've heard of others who use washcoats and others who sand the end grain to finer grits. Only by practicing will you find which works best for you.
From the original questioner:
Thanks for responding. I have always sanded my end grain down to 320. As far as homework that’s what I'm doing now. It’s just that I have not run into this problem before. I never had a customer who had this issue with my work till this point.
From contributor L:
A wash coat has other uses too. The same problem exists when dealing with wavy grain woods (birch, hard maple, pine) on their face. Wash coats dry quick, sand quick and improve the finish a lot.
From contributor M:
I have been successful by coating the end grain portions with a 50/50 solution of paint thinner and varnish.
From contributor R:
Interesting about the paint thinner and varnish. That's a heavier mix than I've heard for wash coats. 10/1 is what I've always heard and used for the alcohol/shellac or water/PVA glue. I like the idea of using what one has instead of having to add another finishing product in the shop.
From contributor D:
I once had the same problem. Read Bob Flexner's Understanding Wood Finishes. His solution, and it works great, is to sand the end grain very smooth, at least two grits smoother than the flat grain. Then, stain the end grain. The reason: it’s not end grain itself, but the roughness of end grain that gives your stain more places to lodge. The smoother the end grain, the less "muddy" the stain's effect. It’s possible to get just about as good a staining on end grain, as on long grain, if the end grain is sanded right.
From the original questioner:
I ended up sanding down to 400 instead of using a wash coat and I did get great results. The customer is happy too! If I went with the wash coat I’d have to mask everything else off but the end grain. So I agree with you that the panels came out consistent. The sad thing is I used to sand my end grain down to 400 but stopped because all I thought I was doing it for was to get out the cross scratches and found that 320 was good enough for that. But now I am doing my own finishing, though I do find it fun it has been challenging. I have new found respect for the finishers in the cabinet shops that I used to work in.
From contributor L:
You do not have to mask anything to use a wash coat. Just put your wash coat on the end grain and do the final sanding. It won't affect the long grain finish. Do some more reading and tests before your make assumptions on a process.
