Tyvek

Kittyfaces

CGF II, Certified Grumble Framer Level 2
Joined
Feb 23, 2004
Posts
359
Location
Kennebunk, Maine
I need to buy some Tyvek for a dustcover on a valuable piece of needleart. The Archival catalog has 36" x 70 yd rolls for $175 for a nice looking plain white grade... is that a good buy or should I use what's available at lumber yards? What are some of your experiences?
 
You can get Tyvek from United. #5660 is 36" x 70 yds for $118.90 (though I'm looking at an older price list, so double-check.)

The stuff from the lumber yards will have printing all over it, so you'd have to change the name of your shop to Tyvek.®
 
You can also get Tyvek by the yard from Falcon East (800)546-3774.
The house wrap variety has been sized to accept printing, though I don't think this affects it's nature or chemistry. It is usually in 96" wide rolls.
Just curious why you specified Tyvek over the Lineco archival dust cover product?
 
Wally,

I'm using the Tyvek rather than the Lineco, which is normally my default, because I want to be sure little critters stay away. There may be some good eatin' in these 200 year old pieces. I worry that one of them may be a linsey-woolsey combo. I've also decided to use a technique I once saw in PMF where I'm going to stretch (bottom to top) nylon screen, batting and unbleached muslin over Marvelsealed strainers and then stitch the art to that and then use glass spacers (the customer insists on no matting). Oh yeah, I have to put aluminum tape on the frame too... wish I thought of that in the quote... forgot to quote the Tyvek and strainers too... oops.
 
I use water based polyurethane to seal frame rabbets after the frames are built. No gaps at the corners and it is easier for me to apply.
 
Bob,

I always consider that but I'm always afraid I'm going to buy the wrong thing. Is it as simple as just looking for "waterbased" on the label?
 
I learned a technique from Hugh Phibbs using Marvelseal strips to seal the face of the glazing to the back of the frame. It is one half of the sealed frame technology used for oil paintings. The rest is to apply another sheet of the Marvelseal to the back of the frame to complete the seal. The whole thing is held in the frame with offset clips and a polyflute panel. Any number of additional preservation technologies can be included in the sealed frame to help with the stability of the environment in the frame: Oxygen scavengers, desiccant panels, corrosion interceptors, etc. Hopefully, one of the preservation specialists will chime in here to speak to the appropriateness of each in the given application...Rebecca, Hugh???
The Tyvek is tough, but critters will chew through just about anything to get to food. With a sealed frame they won't know that there is food in the frame. (Remember the TV ad with the zip lock bag filled with meat and the Tiger?).
 
Intersting. Yes, it'd be nice if Rebecca or Hugh could jump in on this. That sounds like a great technique. I think I'll skip the Tyvek and try that out. It'll save me $118 and be better! Yippie!
 
I raise my hand a little to say that we sell Tyvek from Tara for about $80 for that same roll. Maybe we should move those prices up a little, eh?
 
Kitty faces, water based urethane is just that. Any paint store/home depot etc. will carry it.

I know from experience that insects can eat through polyethylene. I have heard that insects can get into the flutes of Coroplast and live there. This occured in Argentenia. I'd guess that any humid, insect-prone climate would have similar problems. I don't know about the insect resistance of Tyvek.

I'm not familiar with Hugh's system of sealing glass to back of the frame (Wally, do you mean like a high class "masking tape the framing package together"?) If so, I'm guessing that this is a stronger version of using the Lineco aluminum/paper tape for the same purpose?

I also don't know if insects could eat through Marvelseal. Since it's used in the food industry, I'd guess not but....

I'm not aware of there being any rigid standards for different framing systems to accomodate for different environments. It's more a matter of figuring out the problem (or potential problem), reviewing the literature, networking with others dealing with the same problems, seeing how various systems have held up over time, using the materials available to us, being on the look out for new materials, using cross-industrial solutions (e.g. the food industry, packaging industries,...) AND, most important, sharing that information in forums like this or publications.

Being in Canada, I had no idea of the problems that those in tropical climes face. So I learn a lot from Wally and Buddy. Hugh's metier is framing systems, so it's always an education to hear what he's working on.

Me, I'm currently working on a huge pressure mount project for WWI regimantal colors and, when I work out all the practical bugs, will share with you all, as it really is a very practical, safe and non-invasive (though time consuming!)method for mounting fragile flattish textiles.

Rebecca
 
Erin, I'll probably get shot or shot at for saying this, but Shellac for sealing frames, when dry is inert and buggies don't like eating through Tyvek or Shellac. Tyvek is really tough stuff and if your mean evil and vicious, there is nothing funner than wrapping presents with Tyvek and ATG (Tyvek LOVES ATG.).

I'm sure that I'm just old fashioned, and there are very new technologies that us old farts don't keep up on that will seal your frame at nine times the cost. But then, thats just IMHO.

baer
 
Baer,

I don't shoot, but shellac isn't inert. It yellows badly and that means chemical changes are happening. A coating of shellac won't keep out insects (little cannibals!).

The point of sealing the frame with urethane is not to keep insects out, but to keep the acids in.

Tyvek is tough, I doubt if bugs could eat through it, but thinking isn't knowing.
shrug.gif


Rebecca
 
Rebecca, I used to believe that bit about shellac yellowing also. Then a furniture restorer pointed out some shellac that was used to hold some fine glass, that had cracked, together. The repair was suspected to have been made during the early 1700s. The shellac was still a very clear blond.

What he pointed out was that it was the wood underneath that was "yellowing" not the shellac. As for chemical changes: no. Once the alcohal has off-gassed "shellac" becomes stable; until alcohal is re-applied for repair, French Polish, or spilt beer. That is why a scratch in old furniture is so easy to repair. Simply French polish the wound and watch it heal. More furniture usage here than frames.

baer
 
Baer,

I'm sure the degree of change depends on the purity of the shellac, and the thickness of the coating. Shellac used to be used to repair glass and ceramics, and I have seen these repairs turn dark brown/orange many many times. It has also been used to varnish paper and paintings and turns very dark, obscuring the image with a dark brown/orange film. Yes, it remains soluble in ethanol, so can be easily removed, media permitting. Change in color is always caused by a change in chemical composition.

Shellac used in french polish is applied over stained wood, so color change is not a problem when used in this application.

Getting back to the original question of sealing wood to reduce acid migration. The Canadian Conservation Institute suggests water based urethane, not shellac. They have the conservation scientists - I'm comfortable following their guidelines.

Of course metal tapes, such as Lineco rabbet sealing tape or Marvelseal, are better than water based urethane.

Rebecca
 
The Marvelseal (metalized polyesther film) is cut in strips and attached to the face of the glazing with archival hot melt glue (a GE product). The Marvelseal is then folded and bonded to itself with heat making a "box" shape with the glazing being the bottom of the box. The glazing is placed in the frame and the Marvelseal is folded outward and attached to the base of the frame with ATG tape.
Once the art package has been installed in the frame a sheet of Marvelseal is placed across the back of the frame and bonded to the strips (attached to the base of the frame) with heat, thus sealing the contents in a Marvelseal package. Support panels and filler board are included in the package to fill out the back of the frame and offset clips are used to hold the package in place.

My understanding is that even the urethane is gas permeable, and the only items used in the frame package that aren't are metal and glass. Even the use of the Lineco metalized sealing tape is compromised when perforated by framers points.

A Florida Cockroach will go through Tyvek like Sherman through Georgia (a very culturally insensitive remark on my part, but graphically necessary) if they detect edibles on the other side.
 
Kittyfaces, if you only need tyvek for this one job, or to try it out, why don't you stop by a construction site. They usually have big scrap pieces left from window cutouts. FREE!

You could put that on the back first, and then apply a more decorative, black or Lineco paper on top of that to hide the printing.
 
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