Sunday, July 8, 2012

Epoxy Variations: III (Finale: Allegro Amabile)

With the cracks in the siding all epoxied up, I had two more epoxy-related tasks to perform before I could start rehabilitating the dormer in earnest: the consolidating of the heavily damaged sill wood, and the sealing of the end grain on the siding. The former task I wanted to do before sanding because I wanted to prevent the many crannies worn in the sill wood from becoming choked with sanding dust, and the latter was simply convenient to do at the same time.

The sill on the dormer is damaged in the same way as those on the south side windows: extreme lignin damage and oxidation from sun exposure. Here's a picture I took a while back, showing the condition of the sill:

Check out the mountain of debris that had built up in the weight pocket!

In any event, the damage is not as deep on the dormer sill, but it is just as severe. Thus, the treatment required here was the same: straight LiquidWood, applied liberally; the only difference is that the wood would require less of it.

So this last variation is essentially a reprise of the Theme, played more quickly and lightly, and sweetly as well, because we don't have to choke on thinner.

Here is the completed treatment:

The top part of the sill didn't need treatment, because it has been protected under the sash. As I mentioned, I've sealed the ends of the siding as well. Aside from the preventing of any absorption of moisture there, I'm hoping it will help discourage further cracking simply by binding the grain more firmly together.

Now, I am ready to sand.

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Ganahl Lumber, Pasadena. They really make a guy feel at home.

Saturday, July 7, 2012

Epoxy Variations: II (Presto)

While I was waiting for the window casing boards to fumigate themselves, I turned my attention at last back to the dormer itself. Obviously the whole thing needs sanding, but there are a few things I wanted to do beforehand. One of these was to glue up the several cracks in the siding on the right side.

Before he abandoned work on this dormer entirely, the contractor did replace all of the siding on the right side save the top piece. You can see here where he shimmed it out to match the old siding:

As you can see, he simply placed the 3/16" shimming piece behind the shiplap, without laminating the two together as I did. You can also see how the new, thinner stock has already started to warp and crack.

Here, you can see that he was not sufficiently careful, when placing the new boards, not to crack the old one:

You see here what I was telling you about the new, thinner shiplap:

When cut in short pieces, it has a tendency to crack. Now it should be quite evident why I took the trouble to laminate the plywood shims to the new pieces of siding to go on the left side.

All told, there were about a half-dozen cracks on this side of the dormer, and I didn't want to take a great deal of time to repair them. So, I used my secret weapon in such cases: one-minute epoxy, packed in a dual-plunger setup with a mixing tip. All you have to do is put the tip on, press the plunger, and out comes perfectly-mixed epoxy that sets in 60 seconds. It's thick enough to fill gaps and thin enough to get into tight cracks. It's great stuff when you're in a hurry.

So I put on some nitrile gloves, started gluing, and in a scant three minutes I was all done, after pushing the two widest cracks shut while the epoxy cured.

Sure, it's a mess, but I'll just sand off the drips as I do the normal sanding of the surface. Problem solved!

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"Mmmmm. . . beefy fresh!"

Friday, July 6, 2012

Epoxy Variations: I (Allegro con moto)

I hope you all had a fun Fourth!

As you will recall from the post before last, my next task is to rehabilitate the window casing boards. I've been doing some work on them since then.

The first thing I did was to wire-brush the fronts of the boards in order to dislodge the loose oxidized paint and dirt, and to sand off the paint ridges and mineral deposits (from water seepage) from the backs. With this superfluous stuff removed, let's take a closer look at what I'm dealing with. Here's a close-up on the tops of the boards, arranged in their proper position on the dormer from left to right:

Note the lack of sun damage on the right one; it's interesting that the right side of the dormer should be so much less exposed to the sun than the left, when the sun's travel is on the right (south) side of the house. Believe it or not, it's the shade provided by the eave that has protected the top of the right board, while the top of the left one is subject to an hour or so of sun at the end of the day; over 126 years, that adds up to 46,018 extra hours of sun, give or take a rainy day or two (and that doesn't include the partial year on top of that), and that may account for the difference. An hour here, an hour there, and pretty soon you're talking about some real time.

Here's a close-up of the bottom end of the backs:

You can clearly see the mill marks on this unsurfaced side (remember, these boards were only surfaced on the front side). You can also see the water damage and oxidation.

For all my wailing, they are actually in remarkably good shape for their age; with the exception of the bottoms, there is no internal lignin damage, the oxidation and water damage are only superficial, and there is no cracking or splintering. They are certainly in far better shape than the casing boards were on the south side windows; all that's wrong with them for the most part is that they are very dry and thus somewhat brittle.

Then again, these boards are off the house, and they are all somewhat warped. As I re-attach them, I need to coax them back into a semblance of flatness without cracking or splintering them.

You may recall that I restored resilience and flexibility to the casing cap I rehabilitated on one of the south side windows by soaking it in epoxy. That was a feasible operation because the piece was fairly small, and was porous enough to provide ample spaces for the epoxy to enter. To give the window casing boards the same treatment would be a huge undertaking requiring great amounts of LiquidWood, and even then the soundness of the wood would not admit the epoxy much further than an eighth of an inch in. No, for this job I needed to take a different tack.

And so, I decided to try an experiment I'd been thinking of for some time: thinning the epoxy. Abatron provides a thinner specifically formulated for their epoxies; it's a foul-smelling brew, like smog concentrate in a can, so I avoid its use; denatured alcohol works very well to clean epoxy off tools and containers, so I use that rather than the thinner for clean-up.

But alcohol only dilutes the epoxy enough to effect its removal; it doesn't actually dissolve it. In this, it is like water with latex paint. A proper thinner must dissolve what it is thinning; it must mix with it so that the thinned material is evenly dispersed throughout the mixture.

My theory was that the thinned epoxy would travel much more readily through the sound wood, and would be transported much further into it by the thinner. Once the epoxy cured and the thinner evaporated, the epoxy density, and thus its effect, would be lessened compared to un-thinned epoxy, but a lesser degree of the same effect is precisely what I wanted, because that was what the wood needed.

And so, after mixing the LiquidWood and letting it sit so that the reaction got well underway, I mixed it thoroughly with an equal amount of epoxy thinner and brushed it on.

As I had hoped, the wood drank the mixture up thirstily, so much so that I had to mix another, larger batch to finish the job. When I was all done and the epoxy had cured, enough remained on the painted surfaces to leave a glossy sheen, but on the unpainted surfaces very little epoxy remained on the surface. In the heavily damaged areas at the bottom, I could have brushed a great deal more into it before the wood was saturated. In fact, the absorption pattern clearly indicates where the lignin-damaged areas are by their relative lack of sheen.

But no matter, for my experiment was a resounding success! I was able to flex the boards easily, just as new boards would flex, and the surface of the unpainted wood was firm and resilient, with all the oxidized wood now incorporated. This is a good thing, for I can't afford to lose any of the boards' thickness, lest they not lie level with the top casing board when they are put back in place.

The only downside is that the boards positively reek of thinner. I might have expected this, had I considered that a great deal of the thinner remains trapped within the cured epoxy. The morning after I applied the epoxy mixture, I was half-flattened by the fumes when I opened the garage door; I had to take the boards outside to make the garage safe to occupy. 24 hours later, the odor of thinner still hit me over the head when I got within five feet of the boards, even out in the open air, although by the end of the day the odor had at last begun to dissipate. This procedure is not one I would recommend for interior wood, needless to say.

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"What's that foul odor?"

Wednesday, July 4, 2012

Happy Independence Day!

Or if you prefer, Happy 4B Day! That's Baseball, BBQ, Beer and BOOM!

For my part, I'll be hoisting a cold Red Tail Ale to those brave souls who, 236 years ago, had the wisdom to know what had to be done, the guts to do it, and the will to make it stick.

Tuesday, July 3, 2012

4/4 Blues

After a good overnight curing, I removed all the clamps and bracing pieces, and found that I had done a pretty good job of gluing the bracing pieces to the siding. I thought they were well out of glue range, but some of the epoxy crept out and seeped between the siding and the bracing pieces, causing a little damage to the plywood backing in a few places when I pried the pieces apart. 

It won't make a difference in this case, but I should have wrapped the bracing pieces in plastic wrap or coated them with mold release compound. Well, this is how I learn.

I mixed up another batch of LiquidWood and brushed it on the backs of the pieces and all of the end grain. After seeing the long-term damage moisture inflicts upon wood, sealing end grain with epoxy is a step I will always take from now on with exterior wood.

The cured epoxy. Notice that it mostly stayed on the surface. This is fine, because I only applied it to seal the grain against moisture, but in retrospect I could have used much less epoxy, because I'm just going to have to sand most of this off. I shouldn't have been surprised, because for one thing, the plywood is only 5 mm thick, and for another, I'd already saturated the other side. In any event, these pieces are ready for patching, sanding and priming.

So, on to the next task: rehabilitating the window casing boards.

What a mess. Weathered, warped, and all chewed up at the bottom end. It's going to take a lot of work to get these boards looking right. It would be so much simpler just to replace them, but there's just one little problem with that: you can't get boards in that thickness anymore.

That's the dark secret of restoring a Victorian: they don't make lumber like they used to.

It's a very complicated story, the history of lumber standards in America since the Civil War, and after some study my understanding of it is yet incomplete. Still, I'll do my best to explain the situation, over-simplifying a bit for the sake of clarity.

At the time the Farm House was built, boards were sold on the basis of quarters of an inch: 4/4 boards were nominally an inch thick, 6/4 boards 1 1/2 inches thick, and so on. I say "nominal" thickness, because boards have never been as thick as billed; the reason for this stems from the fact that way back before the Civil War, sawmills served a largely local clientele; they provided rough (unfinished) boards sized according to local standards, and carpenters finished them by hand on site.

After the Civil War, with the spread of rail transportation, sawmills began to cover larger regions, and with this development arose the need for more uniform standards of lumber sizing, and the increasing speed of development led to calls for pre-finished lumber in order to speed construction.

According to the uniform standards in place in 1885, the rule was that the dried, rough board started out at the stated thickness, and 1/8 inch was deducted for each surface that was smoothed; i.e., sanded or planed to flatness. Virtually all of the boards used in the Farm House besides the framing are 4/4, surfaced on one side ("S1S"), so they are 7/8" thick. So it is with the window casing boards.

Simply put, 7/8" thick boards are not available as stock pieces today. Boards of one inch nominal thickness are now 3/4", or even 11/16". In fact, the stock used to make the new shiplap was 11/16", which is why I needed 3/16" plywood to match them with the old shiplap. The boards used to make the window casing caps on the sides of the house were 4/4 S1S as well; in that case, happily, I had plenty of old beadboard, which was also 4/4 S1S, and plenty wide for my need.

The problem I have in the present case is that the window casing boards are 7 1/2 inches wide, and I have no old stock to accommodate that width. Moreover, shimming new thinner stock out with plywood isn't a viable option, mostly because the edges would in that case be exposed and I could never satisfactorily disguise them.

So I must rehabilitate the old boards, or spend an inordinate amount of money to have new ones specially milled. Yes, time is money, but my time is not that much money. So, as Joseph P. Kennedy (John F.'s father) said, "When the going gets tough, the tough get going."

Of course, he also said, "Don't buy a single vote more than necessary. I'll be damned if I'm going to pay for a landslide." Joe Sr. was no Vince Lombardi. But no matter; I'll take the truth wherever I may find it.

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"Open open open open open open open open open. . ."