Dye Penetration

[John Shillabeer]

How do you prevent wood dye spoiling the inside surface of a bowl?

I have been asked to make a series of salad bowls from cherry or BLM.
The customer wants me to color the outside royal blue. This requires a liberal application of dye to get the required color density. I am using Chestnut spirit stain because it dries quickly and therefore, unlike water based products, should not "travel" far through the wood before it dries. Unfortunately even quick drying spirit dye stain has penetrated through the bowl wall and left a speckled pattern here and there on the interior surface. By the way, the interior is finished with walnut oil and beeswax so there is nothing to hide the speckles.

Is there a barrier that I could apply to the exterior before the dye that would limit penetration while still adhering the dye, or perhaps you know of a different solution to this problem?

I'd appreciate your ideas and suggestions.
John

I've wondered about switching to acrylic paint instead of dye, but have nor experience of paint on utility items as opposed to purely decorative ones.

 

[hockenbery]

If it were me I would use airbrush paints these stay on the surface.
With a surface finish protection it will hold up. A scratch is going to show raw wood color a dent will be the same color. Scratch will usually show through dye. I often sandblast dyed surfaces away.

Finishing the inside first will reduce the bleed through but unlikely to eliminate it.
I did a HF with bright green chestnut stained frogs with black airbrush painted background on the outside.
Finished the outside with multiple coats of waterlox.
Then used black dye on the inside. It made the frogs a darker green. Something only I would know but the pop of the outside diminished.

Wood grain shows through transparent airbrush paints. Multiple coats make the grain show less.
This is the golden color swatch. You can brush this on if you don’t have an airbrush.
You can also mix airbrush paints to get a color match. Do’t have a good reference for this.
I just ask my wife and play with the ratios.

This a color swatch for the golden. Not quite royal blue.

 

[William Rogers]

If possible I would apply sanding sealerbefor applying the dye. This will seal the wood pores, but I’m no expert on dye. I do this when dying just an area that has been textured to keep the dye from popping in the adjacent area.

 

[Bill Blasic]

The end grain are tubes that carry the dye to the outside of the bowl. Perhaps put sanding sealer on the outside of the bowl to stop the dye from going through. When dyeing a hollow form I usually start by putting dye on the inside and let it bleed through so I get different intensities of dye on the outside.

 

[John Shillabeer]

Thanks for your suggestions, guys.

William and Bill: I already use shellac as a sanding sealer and the dye got past what ever barrier it created in the wood. I don't have any experience with any other sanding sealer, which is not easy to find around here, and wonder if it is compatible with the dyes I use. I would not want to use it on the inside of the bowl because of food safety considerations.

Hockenberry: the suggestion about using airbrush paints is a good one. I have no experience airbrushing paints on bare wood, but always in the past I have had a base coat of rattle can paint and always for decorative pieces that don't get washed. So airbrush paints are semi transparent and hardwearing, provided I use something like a urethane finish over the top. That's good news.

The customer visited yesterday and said she would prefer a less dense application of royal blue so the grain will be more visible. That change alone may be all that I need to solve the problem. If not I'll try the airbrush route.

Thanks again for your help
John

 

[Curt Fuller]

Thanks for your suggestions, guys.

I already use shellac as a sanding sealer and the dye got past what ever barrier it created in the wood. I don't have any experience with any other sanding sealer, which is not easy to find around here, and wonder if it is compatible with the dyes I use. I would not want to use it on the inside of the bowl because of food safety considerations.

John

My guess is that shellac uses alcohol as a solvent, the same as the dyes. So the alcohol in the dye is just dissolving the the shellac sanding sealer. You mentioned that you used a liberal application of the dye. What might possibly help is to use several light applications, allowing the dye to dry in between applications, and building up to the color you're after. Also, because cherry and big leaf maple both already have their own natural color, you're needing to use a lot of dye to overcome that color. You could possibly try bleaching the outside of the bowls first and then dying to see if that requires less dye. But in my own experiences with dying, it's pretty hard to dye something that is somewhat thin walled and not have the dye blead through.
As a side note, I've seen some bowls colored with milk paint that are really beautiful. Google that and see if that might be something your customer might like.

 

[John Shillabeer]

Good insights Curt:
I have no experience with milk paint on turnings. It looks great in photos. Does it let the grain show through?
Thanks
John

 

[hockenbery]

The milk paints I have used are opaque.
It is cool stuff.

here is a seed jar form with a feather motif made by sand carving
One coat of blue, the one coat of black.
Cutting it back with the green scotchbrite wears through the layers on the high spots.
So you see black, blue and wood. In this case the Sapeli is turned a bronze color from a reaction with the milk paint.
Gives a nice old artifact look.

 

[John Shillabeer]

Nice effect with the milk paints but unfortunately not what the customer wants. I'll experiment with some on another project. Milk paint is now on my to-do list.
John

 

[hockenbery]

If you use the airbrush paints. You can apply them with a brush.
The transparent paints become less transparent with multiple coats.
So may need to compromise between color intensity and grain.
The colors often become more intense with a finish applied.

As with any experiment in colors it is always recommend to do a trial piece which you seem to be doing.

I remember being disappointed with a piece after one coat of Waterlox sort of blah
Then a second coat hinted that The colors were getting more vivid.
With 4 coats the colors were popping and there was joy in Mudville (apologies if Casey At the Bat is not mandatory reading north of the border)en