Thread: Advice needed - how to prevent bleeding when saining wooden blocks with food coloring

G'Day Mum,
Food safe timbers and finished are on these posts...
Cheers, crowie

Food safe woods

Food grade finish to use over ubeaut water dyes?

Finishing baby toys

FDA approved wood species for food contact - by PRGDesigns @ LumberJocks.com ~ woodworking community

Non toxic paint, safe for infants

Thank you for the links. They are very informative. It took me a while to carefully read through it. I might try to look for u-beaut and/or mirotone. I'm very excited to give them a try!!

PXL_20201117_120539396.jpg

These are the blocks that I have stained recently. As you can see the left side corner has the bleeding problem.

Quote "If you find the colour bleeds it can be sealed in with a thin coat of white shellac prior to the application of the polyurethane" unquote - from the U-beaut water-based dye website. Now, I am confused... I thought the steps are:
1. Sand surfaces with grip paper
2. Wet surfaces with warm water
3. Wait for the surfaces to dry
4. Sand again
5. Apply dye and dry
6. Finish with shellac or beewax+mineral oil

Do I apply a thin coat of shellac before step 5? I thought polyurethane is a type of varnish?? I'm so confused. Please help!

Steps 1-4 are to raise the grain of the wood and prevent the finished item from having a fuzzy feel.
If you use a water based dye then a water based finish will leech the dye from the wood. Polyurethane will not affect the dye but is food safe once it has dried.
If you read through Crowies second link above, Neil (owner of Ubeaut, and these forums) explains it well in a recent post on a similar thread.

Thank you for your reply! In the photo, the blocks were dyed with food coloring (diluted with water), but I haven't apply any finish yet. I was planning to use beewax + mineral oil. But after reading Neil's post, I am tempted to try the White Shellac (dewaxed).

I think I should put it this way, what are the steps I need to do in order to prepare the wood so it won't bleed like in the picture. I might not have explained very well, sorry.

How are you applying the stain? What is your process?

It looks like its dripping/running from the end surface. Too wet?

You could try:

• masking tape around the edge
• put dye mix in a dish
• On another dish put some of the dye - not too much
• Dab cloth into dye
• Tap it down on some paper so that you can see you are getting some transfer, but without big blotches
• Load and unload your cloth until you are happy with what you see
• Tap the cloth down on your piece, repeatedly until it is even
• Remove masking tape and check no runs
• sit face down on something like a wire baking grid, a couple of nails, whatever to dry
• Do the other end, then the sides

Thank you for the steps! I tried to follow this youtube video Dying wood with food colouring. - YouTube. But I think you're right, they might be too wet. I dabbed yhe blocks with the wet (dye filled) rags. I'll give it a try again with some fresh blocks.

Hello SuburbMom

How fine are you sanding? I would say probably no where near fine enough.

Are you using a sander or sanding by hand. Hand sanding on smaller objects is way harder for smaller objects like blocks.

If you have a sander what type is it? Belt sander, orbital sander or random orbital sander? It does make a bit of difference which you have.

Fixes.... Hopefully.

• The finer you sand the better and easier it will be to dye and finish the blocks ideally sand up to 800 grit or even 1200 those finer grits are available from any paint or hardware shop. The finer ones may only be available in the black Wet and Dry abrasives. Ideally start with 180 grit any courser will give too much scratch marking on the wood making it harder to remove the scratches.

• Sanding grits to use: start with 180 then 240, 320, 400, 600, 800. Get some 1200 as well and hang onto it for now.

• Pay particular attention to the end grain sanding all sides are important but the end grain may need a bit more. The fine sanding will tend to close the pores a little due to slight hardening from sanding, wood should almost shine.

• DO NOT WET WITH WATER this will only serve to open up the grain and swell it somewhat as well as moisten the wood allowing the dye to penetrate deeper into the end grain.

• Use U-Beaut Sanding Sealer: This is a shellac based sealer and one even light coat ragged onto the blocks will raise the grain that has been torn by the sanding. Allow the sealer is fully dry a few hours or even over night.

• Wipe off raised grain with the 1200 grit. DO NOT SAND just wipe the abrasive over the surface this should get rid of the raised grain and leave you with a silky smooth surface.

• Apply the water dye and it should go into the timber reasonably evenly. The end grain may be slightly deeper colour but that's almost inevitable as that is the top or water source of the wood. However it should not be anywhere near as big a difference as before.

• Allow the dye to dry fully at least over night. Before finishing the blocks with the White Shellac. If it is not fully dry then you may get a milky look to the blocks due to reaction from the water trapped in the wood.

• Many other surface coatings will work over the top so long as it is not water based. Bo not use wax or oil as most will allow the oil to leach out if they get wet. Shellac is the safest finish as it's food safe and easy to repair if needed down the track.

Bit of a helpful hint:
If you're going to buy the White Shellac for the final finish you don't really need to buy the Sanding Sealer. You can make your own by pouring a little of the shellac into a glass jar and adding around 8 to 10 parts of methylated spirits to it. That's basically what our sealer is and it is one of the few sealers/retarders that will allow water dye to penetrate into the wood.

Hope this is of some help to you.

Cheers - Neil

Thank you for your reply!! It is very helpful! You are right, I only hand sanded the blocks, that's probably the problem too, apart from being too wet while dyeing. I'll follow your instructions and see how it goes! I'll keep my fingers crossed

Try taping or gluing (with reusable contact adhesive) your abrasive paper to a board and rubbing the block sections on the board. Will be way easier than holding block in one hand and rubbing it with the abrasive in the other hand. Don't use double sided tape inder the abrasive paper s this won't allow you to get a flat sanding surface.

If you can clamp it to the bench or table you will be able to to use 2 hands on the blocks to give you more control the sanding. Sanding preparation is the most important part of getting the dye and finish to be the best.