*Edited- How do I seal the tray on a wooden high chair?

If it is not actually going to used any polyurethane, varnish will be fine. If it will be used the the only finish that is food safe is shellac. for the strap, You can buy strap webbing and belt clips that can be looped around the spindles. Michaels and Hobby Lobby carry them.

I would give it a light sanding and then rub it down with a food grade mineral oil. The mineral oil will keep it from cracking over time. Like a good butcher block, you will need to re-apply when it appears to be drying out. To clean it, use a solution of 50:50 vinegar:water. Do not use soap.

Here are some more general thoughts on finishes that we share with our customers looking for "safe" finishes:.....

All the toxic lead-based dryers used in the past are gone from the paints and finishes woodworkers use for interior wood projects (and from exterior finishes as well, though some marine coatings for boat bottoms could contain high levels of metals or other "toxins" designed to inhibit organisms from growing.)..... Once the solvent that carries the "solids" part of the finish has evaporated and the finish is fully cured (no more finish smell when you take a whiff with your nose next to the finish), the coating is safe to come into contact with food or the mouth...... The solvents in a finish, in its uncured liquid state, are a different issue. Some of the products labeled as a "Salad Bowl" finish have poisonous solvents (paint thinner) in them. But once the thinner evaporates, the coating you are left with is often cured tung oil/alkyd resins (varnish). While varnish is not intended to be eaten, if you should ingest some bits from chopping food on your counter top with the cured finish, you may eat small amounts of the inert material. Consider it unappetizing, but not inedible from a food safety-standpoint......Shellac is often used for children's toys and furniture. A discharge from the lac bug (in Asia) is what shellac solids consist of, thus it is very natural. Of course, denatured alcohol is the solvent for shellac, which if you drink it, will harm or kill you. But the solvent evaporates and what is left is the shellac. Shellac is used widely in the food and pharmaceutical industries to coat food and pills. You could use 200 proof grain alcohol from the liquor store to mix up pure shellac flakes. It would melt the flakes and serve as a carrier so you can apply the finish. Grain alcohol is not poisonous like denatured "wood" alcohol, and so some people may experience less sensitivity to being exposed to grain alcohol instead of denatured alcohol...... There are some finishes in the market place that contain no solvents. These may better protect the person actually applying the finish than other finishes because they may not have any solvent fumes, but be wary of any label throwing around the word "natural". The government has no definition of the word that must be strictly adhered to and thus, while non-toxic when dry, most of today's finishes still have solvents that have health issues if you breathe or are exposed too much to the solvent. Women who are pregnant should avoid applying solvent-based finishes. Always read and follow the manufacturer's safety precautions on the product's label......Some people will use mineral oil on a butcher block counter and wooden utensils. This is a non-curing oil finish. It fills the pores a bit on the wood but doesn't do much in the way of protecting the wood and will evaporate with time, needing to be reapplied. But it is better than applying nothing...... There are some plant/tree curing oils that have no solvents which are heat treated to allow them to dry fully (albeit the process is a bit slow). If you want to consider a walnut oil finish, this one is a great option...... The main reason for applying a finish to a wood project is to mitigate the seasonal movement of moisture in and out of the wood. An adequate finish assists in keeping the joinery work from failing over time by minimizing this wood movement. Of course finishes also offer protection from spills and stains and can give a glossy surface look to the furniture to varying degrees...... You can safely use just about any oil or water-based polyurethane, varnish, lacquer, shellac, or wipe-on finish. Just let the finish dry well before use. A finish that is dry to the touch may not be "completely cured". If you put your nose to a dry finish and cannot smell any solvent, the finish is completely cured. This may take a couple of days (shellac) or up to three weeks (some wipe-on oil/varnishes).

Hey, Is this being used with a child? If so be sure to use something very non-toxic and food safe. You can use the same products used to finish a cutting board, like beeswax or cutting board finish (I think clarks makes some) then there is no worry about it being toxic and you'll probably clean it just as often as a cutting board.

. Liberally brush on polyurethane (you can use water basedd, but oil based will give a prettier result. brush smooth, and lay flat to dry. Next day, turn over and, after sanding brush slides and bottom of tray with poly. Third day, turn over, sand very lightly, dust off and put another coat of poly on top and arms- brush smooth.

Enjoy - should be good for years.

For the belt you could always use a webbed belt that is no longer needed. Just cut in half and fasten it to the chair seat underside. Just make sure that it is child safe fastener/closure (so that if you have to get child out in a hurry you can.) You may want to think about a safety piece for between their legs. Because most kids will try to wiggle out of their seat and straggling themselves with the belt

You can always just use any of your kitchen cooking oils to seal the tray and any other kitchen items that you want to keep looking good and yet still be food safe. The first application will have to be generous and let it soak in. You may find that you have to reapply several times before it stops soaking in. Once you are happy with the look, you can leave it at that. Just wipe over as normal and re oil when ever you think about it.

As for the strap, I agree with these saying about webbing.

You can buy a "butcher block" sealer from the box stores...I use it on my counter top on my island!

Butcher block oil would work fine. I was also thinking about a marine spar varnish as that would be pretty durable. Surface prep will ALWAYS be the key to a good job.........and the most work. Good luck.

I always used a towel wrapped around the child and tied in back

Zinsser bulls eye shellac is non toxic. The straps you can buy online. Pinterest has a whole diy article.

My friend suggested that also. It may be what I do over Christmas, then I will figure out something.

You may want to use a bar top finish. It is extremely durable and safe.

Wooden bowl finish (food safe wax). https://jas-townsend.com/advanced_search_result.php?keywords=BF-292

I have done alot of wood working, and have made chairs similar to this (from an old chair I used as a pattern). . . ..

I would use gloss polyurethane...water based is nice because it is basically no-odor & water cleanup when wet. . . . However, I would recommend the regular polyurethane, as I have found it to be more durable, lasts longer, and from my experience using the water based poly, it has a tendency to dry cloudy, depending upon the humidity.

Use 3 coats & allow to dry at least a couple hours between coats. When thoroughly dry (24 to 48 hrs). Wipe down the surface with soap & water, dry off completely & finish by wiping down with 70% or 91% rubbing alcohol. . . That will make it safe for food use.

Thanks for sharing.

I use coconut oil to seal all my hard white maple. Melt it down, let it sit and wipe off excess. I use it on my butchers block and my counter tops. Or use fractionated coconut oil.

As far as lead paint; I understand your concerns. It can be dangerous. I think a sealer might work or painting over it.

Strapping the baby in; maybe taking apart an old back pack with adjustable straps with male and female ends and sewing them around the back of the chair. Buying one at the goodwill if you have the funds.

Thanks Bernice, I have received a lot of good advice. The goal is to have it done by Christmas.

When using mineral oil, your wood must be bare though. It's great for butcher block counters, cutting boards or furniture brought down to the bare wood but doesn't work if you're using paint and certain stains as well.

I actually have a question about your chair. Do you have any details as to the company that made it or when it was made? I have the same one and am trying to track down info because it's been passed around the family so many times.

Hi Lou, hope this help[s you out. I would go with a urethane.

https://www.apartmenttherapy.com/a-safe-nontoxic-sealant-for-a-127117