Preventing Blotching on Vertical-Grain Fir

Tips on using a clear wiping stain base before the tinted stain, and related advice to prevent blotchy results. April 30, 2009

Question
I'm staining cabinets for a house with a ML Campbell wiping stain. Staining the sheet goods is fine but the solid wood is a different subject with a lot of black blotchiness. According to the can, no sealer is necessary or recommended. Any hints as to how to overcome this blotchiness?

Forum Responses
(Finishing Forum)
From contributor I:
The fir, as with many softwoods is going to be prone to blotching with most stains. If there is an opportunity to start over you can use one of their microtone products under the stain, which helps or you can try one of the time tested methods like glue sizing, per conditioning, and etc to reduce the blotching. The hard part is if you already started the process on the actual project. If you are preparing test samples you can make the adjustments now. If it is too late remember that for the next job. In the future look into the ICA CNA spray stains. They are excellent on soft woods.


From the original questioner:
I was going over some notes from a class I took with ML and they had mentioned a 10% wash coat on blotchy woods. I'm not too far along in the project as most that I've stained so far is for cabinet interiors and therefore a more consistent look anyway. I'm about to go experiment a little to see if the washcoat helps.

From contributor F:
When I took the ML spray course, one of their solutions for blotchiness was first staining the piece with clear wiping stain base, let dry, then use the wiping stain. It works very well on cherry, and helps on maple.

From the original questioner:
At first my ML rep was going to start with a 10% stain base and then go to the full stain but then decided it could be done in one step - not a very dark stain. In hindsight it probably might have helped like what you mentioned.

From contributor F:
Whenever I have to use a wiping stain on a wood that is even slightly prone to blotching, I always wipe first with the stain base, let dry, then proceed with the tinted wiping stain. It’s actually surprising how well it works. Works okay on maple with light colored stains, but not great.

From contributor R:
Some of the "gelled" type of stains I have tried worked pretty well on maple and cherry. Rotary and other cuts of fir might well benefit with a sealer coat of sorts prior to staining. Just because the can says it’s not necessary to apply a sealer coat is just one reason to create a complete sample from start to finish. If you had done that you could have called the can a liar right to its round face.

From Paul Snyder, forum technical advisor:
Usually whenever I use a new stain, even if it's just a new color from the same brand I normally use, I'll do some sampling on the veneered ply and solid wood from the job. But one time I used a new color and only did the sample on veneer. It looked fine and I started in on the cabinetry. We were doing European cabinets so there weren't any face frames.

The boxes all stained nicely and then I started in on the doors. The first door I started with blotched so bad it looked horrible. Since the cabinet boxes were already stained, I couldn't change the schedule and use different steps/products to avoid the problem. I had to use the same stain.

So what I did was seal the doors with a washcoat of vinyl sealer, stained them, and sprayed a coat of sealer. Because the washcoat partially sealed the wood, the stain didn't soak into the wood as much and the color was lighter.

To add more color, after sanding the sealer smooth, I added a little of the stain to some highly thinned finish and sprayed on a very light, even wet coat. Using the stain as a toner kept the color the same and made it as dark as the cabinet boxes. Right after the toner flashed off, I sprayed the topcoat. The color was more even on the doors than it was on the boxes, but it looked good and no one besides me ever noticed.

Make a Washcoat to Eliminate Blotching


From the original questioner:
Thanks for the advice. I've been so busy lately, I should have spent more time making sure I had the whole process down. I probably let that part slide and just figured the tech matching the stain sample to my sample would lay the whole process out to me and that probably wasn't a fair assumption. I'm a cabinetmaker first and a finisher second!

As it turns out, the painting contractor that did the millwork is going to do the finishing so everything will match and I don't have to match them but with different products. I've worked with them a lot so it should be fine. I'm way behind schedule on this and the contractor is getting a little upset. It's his own house and as about 60% of my work is with him, I need to keep him happy! This has definitely been a learning experience though.


The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor J:
My father was a painter's apprentice back in the 1920's. I was once building a pine chest for a client who wanted it stained and I called my dad to see if he have a remedy for blotching on various woods like pine, maple, birch, and etc. His solution was to take a quart of beer and pour it in a bowl, let it go flat, coat the piece to be stained, let dry and lightly sand with fine paper. The minute solids in the beer fill the irregular grain holes and even out the stain. When he first gave me this advice I thought it was a joke until I tried it and it works better than anything else that I have tried since.

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