Weakened Defected Wood

[Sonny]

Some long time ago, on some forum, I read of a product that resolidifies rotten, termite-eaten/powderpost beetle-eaten or otherwise weakened or defected wood. Can someone direct me to this product, if there is such, or a remedy for severely defected wood? Removing part of the defects is an option, but in some places, glueing new wood strips isn't an option, to restore the integrity of these areas.

The specific problem is, regarding upholstery, the mangled, softened wood along the decorative nail paths on an antique chair. There are numerous nail holes in the wood, from having been reupholstered several times before, and much of the wood is "chewed" to "softness" and/or seems to be in a soft dry-rotted state. The wood is no longer stable enough to hold new nails. I've had success with bolstering similar wood defects, as this, but this case is much more severe.

I've thought about epoxy glue, but I have no experience, at all, with epoxy glue, so I don't know if epoxy would be brittle and chip out, when nailed into, especially along these narrow nail paths.

Thanks for any help. Sonny

[keithw86]

For "dry rotted" wood I've had excellent results from this stuff:

The specific problem is, regarding upholstery, the mangled, softened

Since it's interior, would "plastic wood" work?

[Max]

I've used this product on small projects. Worked well.

[GROVER]

Have you considered Bondo? Originally used by auto body shops, its a two part system which is moldable.I have useed it with success in the past.

Joe G

[StephenM]

Yes, Try epoxy.

Ideally, you would like low-viscosity epoxy such as what comes in a kit like this:

have used this product and it it worked well. But it's pricey and I think there may be a cheaper solution.

One think about epoxy is that it is very temperature sensitive. When warmed, not only does it cure more quickly, but it looses most of it's viscosity as well. Warmed exopy will be almost as runny as water.

pick up some slow-cure epoxy at the hardware store. Mix it up and apply it to your "punky wood". Hit it with a heat gun or a hair dryer. The wood fibers will soak it up.

I don't know how well fully cured epoxy will take nails, but if it's 90% cured (like somewhere between 4 hours and 2 days depending on the type of epoxy and the ambient temp.), I'll bet it take nails really well.

Lew.... this is your cue to jump in.

-Steve

[Chasgroh]

...I'm into a project that will require something like we're talking about here. Basically a slice of a tree so it's *all* endgrain...I've flattened it and dried it out to the point that I think it's done contracting. There now is a check or two that I must fill with something that will withstand the movement of the wood but still retain some charactoristics of the wood. I use bondo for paint grade repairs frequently and it's wonderful, but on this it's got to be some kind of epoxy that I can color...this discussion is very informative.

cg

[eclipsme]

Git-Rot. It is a low viscosity epoxy that soaks into the wood fibers. It was used years ago on the Balclutha in San Francisco to preserve her.

[Lew Hodgett]

------------------------------------------ Epoxy and micro-balloons would be my weapons of choice to attack this problem.

Removing the damaged wood fibers, then back filling with micro-balloon thickened epoxy will provide an incredibly strong repair.

There are specialty epoxies that are very low viscosities from people like RotDoctor and GitRot that have been around forever for the wooden boat repair market.

Based on your description, there are probably less expensive and better repair methods using standard laminating epoxy.

A question.

Are the nails and staples used in these repaired rails driven with a hammer or a pneumatic gun?

Lew

[pcfixr]

A penetrating wood epoxy that is non pigmented and does a very good job of absorbing into most wood is this stuff called CPES (Clear Penetrating Epoxy Sealer). All of the fillers used to make putty and or thickened epoxy can be added as necessary. (milled glass fibers, cabosil, etc)

Joe. [e-mail]

[Larry Jaques]

On Fri, 5 Mar 2010 20:44:10 -0800, the infamous "Lew Hodgett" scrawled the following:

Lew, being the resident epoxy expert, I was hoping you'd also have some words about the MinWhacked "wood hardener" crap. That kind of product has never worked as stated.

-- The blind are not good trailblazers.

-- federal judge Frank Easterbrook

[Sonny]

Lew, is there a particular concern you have in mind, as to hammered vs pneumatics?

I've emailed, with pictures, RotDoctor for advice on their specific product recommended for this particular woodwork. I've also purchased, locally, some Loctite epoxy and it's being tested at the moment.

The new decorative nails will be hand nailed, individually, with a vinyl head upholsterer's tack hammer. I'm not aware of a pneumatic nailer for decorative nails. In any application, whether the wood is in good shape or not, you have to be careful of splitting the wood because of the numerous inline nails being installed, i.e., creating a perforated (perforation?) line that the wood may split/crack along.

Staples will be installed with a pneumatic stapler, 70-90 psi. Again, numerous inline staples can sometimes result in splitting of the wood. Staggering the staple prongs, by twisting the gun a tad, helps eliminate an inline arrangement.

In each case, you kind of have to assess things, before stapling/ nailing away. I don't think I've ever seen an antique that hasn't had excellent wood structures, but even nice antiques have had wood to split along these nail paths. In some cases, stressed fabric, when in use, has "pulled" enough on the nails/staples to cause the wood to split or crack, rather than the nails/staples dislodge, first.

This is an interesting restoration project, even for myself. Some of these nail paths, the wood, has been altered from the original, no doubt because of previous issues during previous reupholstering. Some nail paths have, literally, been cut off, in some areas, and wood strips have been nailed back in place, for decorative nail reattaching. This nailing of these wood strips seems to be the equivalent to the nailing of the doweled ends of chair's stretchers back into their holes.... that kind of "repair". Even these newer wood strips need to be snugged up a bit more and glued. So for, the restoration has been going smoothly.

Thanks for all the advice, info and links. It's really been helpful. Sonny

[Lew Hodgett]

----------------------------- I'm clueless.

Lew

[Lew Hodgett]

----------------------------------------- The reason for asking is that driving a tack by hand into thickened epoxy after allowing it to set up for 3-6 months might be a challenge.

My gut says "No problem", but I just don't know.

I'd contact:

knowledgeable people, I've used thousands of gallons of their stuff.

They are serious players in the epoxy business.

----------------------------------------

No longer a problem with a good epoxy repair.

----------------------------------------

Even these newer

----------------------------------------

Which brings up the question, if you make a repair using current technology (epoxy), does that reduce the value of the restored chair?

Seems to me adding wood strips to repair is old technology.

Does adding wood strips affect the value of a restored chair?

Lew

[Larry Jaques]

On Sat, 6 Mar 2010 12:46:27 -0800, the infamous "Lew Hodgett" scrawled the following:

Oh, I thought that might be only when you were at the polls.

-- The blind are not good trailblazers.

-- federal judge Frank Easterbrook

[blueman]

I would not use Bondo. I don't think it is good at taking screws and nails.

[blueman]

I'm a big fan of West Systems. I spoke to their tech support and they said it is much better to use their warmed undiluted epoxy which has a similar viscosity than to use on of the kits which relies on diluted epoxy -- bottom line is that you will get better hardening and bonding using undiluted epoxy while warming will give the same penetration. Also, when bought by the gallon, West System is significantly less expensive.

One tip -- heat the *wood* surface rather than the epoxy (e.g., use a heat gun). First, this will do a better a job of wicking in the epoxy since it literally draws it in. Second, by not heating the pot, you don't run the risk of overheating the epoxy or speeding up the hardening too much.

The problem with most generic hardware store epoxies is that they come pretty thick (presumably various thickeners have been added like silica). Even with heating the wood (or the epoxy), it may not be viscous enough to wick in. West Systems sells resin and hardener that is neither artificially thickened nor diluted -- if needed, they sell various fillers to modify the properties for bonding, filleting, wood-fill, etc.

[blueman]

I would still recommend a two-step approach.

First coat with low viscosity epoxy to penetrate and firm up any remaining weakened material along the edges and to create a good adhesive layer. (as mentioned in another post, I like to use West System without fillers and heat the wood to draw in the undiluted epoxy. This according to West tech support achieves the same penetration as the alcahol or mineral spirits diluted epoxies but has better adhesion and stength since the epoxy is not diluted).

Then I would use low density microballoons mixed with epoxy to bulk fill and replace the removed or rotted materials. If you want a screw or nail to hold you may want to use more of a medium density filler.

[blueman]

In my experience, it shouldn't be a problem if you use the lower density fillers. They tend to work and shape like wood (depending on the ratio -- the more filler you add, the less hard)

[blueman]

It smell awful and probably causes cancer in rats in a 5 mile radius - other than making the wood a bit sticky and tacky, I haven't found it to do much hardening. The nastiness of the chemicals might prevent future rot for a while by sheer toxicity to the microorganisms...