Archival storage of prints and plywood

[jonathan.lipkin]

I have a show coming down that I want to crate up and store. Most crates that I've seen are made of plywood. Does anyone know if outgassing from the plywood is a problem? The gallery director doesn't seem to know.

The photos are Epson pigment inkjet prints mounted on sintra, so I'm not sure that they are archival at all - the mounting was done by a very good laminator, but I don't know about the adhesive they used.

I can't think of any other material to use - MDF or chipboard would be no better in terms of outgassing, I'd think, and other materials would be too heavy or expensive. Would polyurathaning the plywood help? http://www.artcrating.net says they shellac the exteriors of their crates, which look like veneer ply, and most other places seem to use plywood as well

[framah]

Completely ealing the wood would be the only way using plywood or any other wood wold be acceptable for storing your work.

Anything dry mounted to anything is not archival. Even with that info, you would still need to seal the wood so the formaldehyde and other toxic chemicals in the glues used to make the ply can't outgas.

[jonathan.lipkin]

Thanks, F. Would polyurathane be the best way to seal? How long do I need to let that dry before closing the case?

[framah]

Not sure about either question. i think Poly would work fine. no idea how long to let dry. You might try googling specs on the poly to see if there is anything about it.

Here's a weird thought... what if you built the box and then drilled a couple of holes in the sides and installed vent caps that would allow air in and out but keep bugs out.
Just thinking here.

[AFairley]

Completely ealing the wood would be the only way using plywood or any other wood wold be acceptable for storing your work.

Anything dry mounted to anything is not archival. Even with that info, you would still need to seal the wood so the formaldehyde and other toxic chemicals in the glues used to make the ply can't outgas.

But the real question is whether anything the plywood would outgas would be detrimental to the artwork in the first place. I have no idea myself.

[Alan Goldhammer]

Any material that has the potential to outgas or has potentially damaging chemicals in it (and this includes many kinds of paper envelopes) will possibly damage prints and mounting materials.  I had a recent experience where a forum member in Germany sent me some targets on Museo Textured Rag for profiling.  The prints were mailed in a paper envelope with cardboard backing and were in transit for just over two weeks because of an improper postal code.  When I opened the envelope each of the four prints was noticeably yellow, most likely from the mailing materials which were probably acidic and had some other residual chemicals in them.  Some of the yellowing was gone after exposure to air and light but the paper never returned to the true white value.

Since plywood and other like composite materials are inexpensive, they are often used for shipping containers.  One possible way to mitigate any damage would be to carefully wrap the prints with high quality polyethylene or polypropylene (similar material used in archival print sleeves) which will minimize any gas getting to the prints.  For long term storage, I would not recommend such materials.

[framah]

You could also look for a museum in your area and ask to pick their brains about this stuff.

[Kirk Gittings]

I've had a few framed exhibits of my dry mounted gelatin silver work put together by museums for traveling shows. I every case the shipping container was made of unsealed plywood and they were stored in the same containers long term-going on 25 years now. In 2005 I had both exhibits pulled from storage so a 30 year retrospective could be cobbled together. There were no adverse effects that I could tell.

[EricWHiss]

If it were me, I'd put all items inside sealed plastic bags, because I know that moisture gets through the wood over time, plus all kinds of other stuff.  If you crate inside you may open later to find mold, etc.  I don't know about bags for long term archival, but if they are okay then you don't need to worry about the wood.

[ckimmerle]

I'm with Kirk on this one. I wouldn't worry about wood crates. Museums routinely use unsealed wood boxes, either plywood or OSB, for shipping and, if necessary, storing artwork. I had to make four shipping crates for my last exhibit, which traveled to 10 different galleries/museums over the past year and a half and, when I get them back in February, I'll be using the crates for storage.

What I would not use, under any circumstances, is exterior-grade sheet stock (green or brown treated) as, unlike interior plywood or OSB, they're usually sold "wet", and will give off a lot of chemical evaporation.

As for storing inside plastic bags to protect against moisture that may permeate the wood...unless those bags are hermetically sealed, they won't do much good as any humidity will find it's way to the artwork. However, if you have to worry about the crates getting wet, they you really need to think of another location.

[jonathan.lipkin]

I did a little more research - checked Harry Wilhelm's Care and Permanence of Photographs. He does not recommend long-term storage of prints or anything in ply: Museum of Fine Arts in Boston found corrosion in metal storage containers which they traced to formaldahyde from plywood, and the Sackler Museum at Harvard also measured high levels of formaldahyde in ply containers. Sealing with three coats of polyurathane did not stop the off gassing. He also mentions that formaldahyde can react with some of the chemicals in B&W film and paper (I think the silver halide, but did not write this down). He feels that this would more seriously affect older B&W emulsions. Finally, he does not recommend the use of any wood because they may release peroxides.

In any case, I think I'm going to simply make plywood cases after all. The other alternatives (he suggests enamled metal, certain kinds of plastics, among others) are simply too expensive.

Thank you all for your comments.

I'll post pictures as the project progresses

[ckimmerle]

If you're worried about out gassing, then make sure you don't seal the boxes to allow air exchange. That is what I am planning on doing when my four crates come back, but I forgot to mention it in my earlier post.

Good luck on the boxes.

Chuck

[Kerry L]

"Material is closed-cell, expanded plastic, high-density poly vinyl chloride sheet. It is acid free and has minimal out gassing for Archival use." This from the manufacturer of Sintra.

Perhaps lining the wooden crates with Sintra with some venting is a workable alternative.

[jonathan.lipkin]

Interesting. The prints are mounted on Sintra.

[jonathan.lipkin]

I wanted to report back to you after I finished building the crates. After soliciting lots of advice, I decided to build the crates out of 1/2 plywood, using ethafoam - an archival packing foam - to hold the prints in place. I had the lumber yard mill the plywood to size, and used a table saw to cut the ethafoam. I used a dado stack to cut the grooves. The ethafoam attached to the ply with hot glue (archival hot glue is available, but I did not use) and I put a few dots of gorilla glue in for extra grip. Getting everything to line up was a bit tricky, especially as hot glue only allows you a few seconds of working time before it sets up. But, crates are assembled and ready to go. The largest crate - it holds 17 24x26 prints - probably weighs 300 pounds. I may put casters on the bottom to wheel around.

[framah]

Nicely done!!!