Conservation Wood Sealer options?

John Ranes II CPF GCF

SGF, Supreme Grumble Framer
Founding Member
Nov 5, 1997
Appleton, Wisconsin, USA
The Frame Workshop of Appleton, Inc
Beyond my area of expertise, I received an email from a very good framer who had the following question.....
I was wondering if you could help us with a conservation question/problem we are having at one of our frame shops.

We are hearing complaints from a few of our associates that the poly acrylic sealer we use on wood frames in our conservation framing is toxic. My understanding is that the issue is not that product has a strong order, but that it's considered toxic (ie, it doesn't have a "non-toxic" label).

We are currently using Minwax water based polycrylic, in the clear satin. We coat the exposed wood 3 times with the product, letting it dry between stages. The associates have tried the Lineco Seal tape and are unhappy with difficulty of applying the product.

My question is: Is there a product that we can use to seal our wood frames for conservation quality framing that is non-toxic? One that can meet the conservation standards of sealing a frame, yet would be considered and/or labeled non-toxic. Or even, is what we are using non-toxic, even though it's not labeled as such?

I honestly believe what this fellow is doing is OK....but would appreciate some input from the conservators / chemists amongst this group....Hugh?


John, based on some recommendations I received right here on The Grumble, that's exactly what I use.

The label says: "This product contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm," so I wouldn't use it in California or if I were pregnant.

It also says "Conforms to ASTM D-4236. Contact a physician for more health information."
The associates have tried the Lineco Seal tape and are unhappy with difficulty of applying the product.
NO wise cracks Less!


I find Lineco tape much easier and faster than a paint-on-sealer.

ok, just one
AS has been noted, water-based polyurethane is
commonly used in museums for discouraging emissions from wood. The most sought after are those that have the fewest additives. The difficulty in finding such materials is their
rarity in the market place. Generally, they must
be obtained from the factory in large quantities.
If a complete seal is needed, a metal layer will
do the job. If the tape is to difficult to apply,
one can try using strips of a plastic/metal heat
bonding film such as Marvelseal 360. This can be
cut into strips and ironed into the rabbet of
frames. Side grain of wood is not nearly as strong
a source of emissions as end grain is, so many
sealing materials should give good protection.

Rember that products like this are tested and MSDS sheets are prepaired for individuals who use the product on a regular basis in larger that the general quanity that we use ( 1-2 oz.).

Good safety equipment and a proper place for application is a requirement in all situations.

Your framer friend did not state where they are applying the sealer (in the fitting room or by the loading dock, or even out side). Having the frame sealed and allowed to dry in an alternative location would definitely help to limit exposure.
Some mouldings have finished rabbets - many of the Blacks have what appears to be a plastic finish which covers the entire moulding including the rabbet. Perhaps some moulding manufacturers could be persuaded to seal the rabbet while they are spray finishing the moulding - "conservation wood moulding".
The solvents that are present in the material are essentially all gycols of one sort or another. ethylene Glycol being one of them, or antifreeze.

These materials can cause problems in an enclosed space, especially if you throw it all over the place seal the doors and windows and breath deeply for an extended period of time.

Ethylene glycol is considered poisonous in large quantities, therefore don't drink it. That's why you keep your dogs away from spilled antifreeze.

Everything causes Cancer in California and must be labeled as such.

I know this is a little tongue in cheek response but seriously, proper ventilation is the most important percaution. You can use plastic gloves if you are REALLY concerned, but truthfully common sense is a necessity.