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“Chinking” is now commonly thought of as a water-based, synthetic polymer sealant that is textured like mortar and has considerable elasticity and flexibility. Twenty years ago “chinking” was generally thought of as Portland cement-based grout that was applied to the joints between logs, reinforced with metal lath. The new chinking products, such as Log Jam, far outperform the old type of chinking. Chinking
can be used in most places where caulk would be used, but chinking is
more commonly used in large joints between logs and when the building
owner wants the nostalgic look of old-fashioned, textured cement grout.
You do not “have” to use backer rod (which is a type of “bond breaker”). But, if backer rod is not used wherever it is appropriate to do so, then the chances of experiencing a premature sealant failure are very greatly increased. Backer rod allows any sealant applied over it to perform much better than without it. Here are the reasons: 1) Backer rod insures that the sealant is adhered only to the two opposite sides of the joint being sealed – delivering what is called in the industry “two-point adhesion”. 2) Two-point adhesion permits elastic sealants to much more easily stretch – without any concentrated points of stress developing across the full width of the sealant bead – as the joint moves, over time, in response to temperature and humidity changes in the wood (or other material). 3) Backer rod prevents what is called “three-point adhesion” which occurs when the sealant is adhered to the opposite sides of the joint and to rigid material in the rear of the joint. When this occurs, concentrated forces are applied to the back of the sealant bead, usually leading to very early failure (with tearing of the sealant or the substrate). 4) Backer rod greatly helps control the depth of the sealant as it is being installed to insure that the optimum amount of material is put into place. If too little material is installed, premature “cohesive failure” can occur. If too much is installed, premature “adhesive failure” is usually the result, and much sealant can be wasted. 5) Backer rod (especially the round types) greatly favors the development of “cohesive failure” – if failure is inevitable (due to extreme movement or very rapid movement that occasionally – but routinely – occurs with “maverick” logs or the interior surfaces of logs as they go through their first winter with warm, dry air from a furnace). When such “cohesive failure” does occur, it is relatively easy and inexpensive to repair by just cleaning the exposed surfaces that have torn down the middle of the joint and applying additional sealant (and most sealants do adhere well to themselves – but not all, which makes it important that you investigate this aspect of any sealants you may be considering using). Without backer rod, “adhesive failure” is typically the result, and usually the entire bead of sealant needs to be removed, with the applicator simply starting over. 6) Backer rod usually adds additional insulation to the surface of the wall to help reduce heat loss or gain. 7)
Round types of backer rod should be used when the logs are relatively
“green” and are subject to significant shrinkage and movement.
Round backer rod provides the most ideal sealant geometry for allowing
the greatest overall movement capability of all sealants and it also favors
cohesive failure if the movement becomes so extreme that failure is inevitable.
Log Jam, Log Builder and Conceal are very similar in their chemical composition. The primary difference is the type of filler used in each respective product. Log
Jam uses a system of granular particles that imparts a relatively rough
surface texture. It is designed to simulate old-fashioned cement mortar.
Conceal can best be described as a cross between Log Jam and Log Builder. It exhibits a medium texture that is designed to blend in with the surface of the wood. All
products establish high adhesion to various surfaces, including, of course,
clean wood and wood coated with compatible stains or paints. All products
are very elastic, accommodating a great deal of underlying movement without
cracking or pulling away. Conceal exhibits a little higher performance
than Log Builder and Log Jam in terms of adhesion and movement capability.
Log Jam exhibits higher performance than Conceal and Log Builder in terms
of insulation value and fire resistance. Yes,
but the following rules must be followed: A
variety of tools and techniques can be used in apply chinking or caulking.
Most applicators use foam brushes, steel trowels or plastic trowels. In
any case, it helps to lightly spray water on the surface of the material
immediately before brushing or troweling. While still wet, all three products can be cleaned with water while on hands, tools or surfaces. Once the material completely dries it is much harder to remove, and often needs to be cut or scraped off. If the material dries on your hands, you can usually remove it by just rubbing your hands together and it will roll up and off the skin. 7.
Should I caulk my new log home now or in a year
or two? If
not for the impracticality of it, it would be great to allow the logs
to completely acclimate themselves to their new environment and undergo
the majority of their likely movement before sealing the building. But,
moisture and air leaks need to be controlled as much as possible right
from the get-go. So, apply the necessary caulking now – in accord
with all appropriate methods – and plan on performing a little repair
work over the next year or two as the foundation, roof system and walls
settle into place. “Linear
feet” is simply the length, in feet, of the joints (i.e., the gaps)
between the logs or the length, in feet, of the checks on the house that
need to be caulked or chinked. You can measure or develop from blue-prints
what the perimeter length is of your house (sometimes including the log
tails at the corners if these projections will be caulked or chinked).
You then determine how many courses of logs you have and multiply the
number of courses by the length of the exterior perimeter of the house.
If there are large areas with windows that will significantly reduce the
lineal footage of joints, then this – and other similar circumstances
– will have to be taken into account as well. Yes, most stains can be successfully applied over Log Jam, Log Builder and Conceal. However, it must be noted that the appearance of stain applied over chinking or caulking will almost always be different than the appearance of the same stain applied over wood. This is because of the differences in color and surface texture between such sealants and wood. So, before applying a stain to a large area where the stain is being applied to both sealants and wood, be sure you test a small area to confirm whether or not the appearance will be acceptable. Also,
it is important to note that many (but not all) stains are based on resins
or polymers that, when dry, are quite rigid and hard – far harder
and far more rigid than either Log Jam, Log Builder or Conceal. This can
lead to problems later as the chinking or caulking tries stretch to accommodate
the inevitable movement that continually occurs between logs due to changes
in temperature and moisture. Because the rigid coating cannot move nearly
as easily as the sealant, it builds up localized areas of stress and can
cause the surface of the sealant to develop shallow surface cracks, which,
while not normally affecting the overall sealant performance, can lead
to an unappealing appearance. It
is difficult to keep maintenance coats of stain off chink lines. You can
brush on the stain and attempt to keep it off the chinking, but that is
a time consuming effort. Another option is to spray the stain, back brush
it into the wood, and then come back over the chinking with a product
like Brushover. Brushover is our textured, elastomeric coating matched
to our Log Jam colors that you simply paint over the chink line to restore
the original color of the chinking. Log Builder is the leading caulking product in the log home industry. It has tremendous adhesion to all types of wood and is extremely elastic. While Sashco’s Stacker caulk can be used for this application, Log Builder will perform even better.
Yes,
all of the Sashco log home products are made in compliance with the relevant
environmental regulations. Sashco makes every effort to use the least
toxic chemicals possible for its products while still delivering the kind
of performance required for the log home industry. Finally, most of Sashco’s
products are water-based which makes them even more “environmentally
friendly.” Although
this is the preferred look for most homeowners, clear coatings do not
provide long-lasting protection from ultra violet light. Most stain manufacturers
add UV absorbers or inhibitors to their coatings but over a relatively
short period of time these additives slowly breakdown or migrate becoming
less effective at stopping the damaging effects of sunlight. The result
is that either the coating itself or the underlying wood eventually begin
to change color--usually darkening. When this color shift starts, this
is a sign that the wood beneath the coating is beginning to deteriorate,
it is also actually decomposing. Eventually the coating can begin to pull
away from the wood and major lifting and peeling can occur leaving your
logs totally unprotected. Yes, the following are reasons why it is highly recommended to stain your log home. 1) Without a good coating on the exterior of logs, the wood will darken and degrade very quickly when left unprotected against the sun and weathering. 2) Uncoated wood absorbs much more water than coated wood does. When wood absorbs water it swells significantly and then shrinks again when dry weather returns. This repeatedly severe dimensional cycling of the wood leads to the development of many more checks than would otherwise occur and enlarges the size of those that would have occurred even with a coating in place. 3) Without a coating on the exterior surface, sealants applied to the joints between logs or to large checks usually will have a very difficult time maintaining adhesion to the wood. The reason is that wood, especially when wet, becomes very, very difficult to adhere to by any type of sealant, and uncoated wood becomes far more saturated with water in the immediate vicinity of the bond-line of the sealant than does coated wood. 4)
Coatings, by repelling a large volume of moisture, help prevent mold,
mildew and rot from occurring. These fungal organisms require moisture
in order to survive and thrive. Consequently, the more moisture you can
keep your logs from absorbing – with a good quality coating on the
surface – the more you minimize the potential for fungi to do damage.
Typically
on the southern exposure of a home, a stain may last 2-3 years. On the
other sides of the home a stain can be expected to last 3-4 years. These
numbers are just estimates and can be greatly influenced by the following
factors. The
minimum temperature should be 45 degrees and rising. The maximum temperature
should be below 90 degrees. It is important to note that this is in reference
to the temperature of the logs. It is always best to stain first for the following reasons. 1) Stain, being a thin liquid, generally has a greater ability to penetrate into wood (especially when it is properly back-brushed during application) and establish better adhesion to the micro-porous wood than does a thick pasty material like caulking or chinking (which generally cannot penetrate as well, even when tooled). Consequently, a compatible stain can act as a primer for caulking or chinking, further enhancing a sealant’s adhesion to the logs. 2)
It is much easier to clean the surface of the log with stain on it as
runs occur of tooling water when these runs flow down on the upper curvature
of the lower log. Bare wood absorbs the polymer-laden tooling water, and
it dries out much faster (leaving potential stain marks) than it would
on wood that is previously coated with a stain. Proper
log preparation is a large factor in the success of the stain material.
Logs that have been exposed to the elements need to be cleaned through
sanding or some form of blasting. Even new logs need to have the “mill
glaze” removed before the application of stain. This can be done
through the previously described methods. This step should be done no
sooner than a week prior to staining. In conclusion, virtually all logs
need to have some form of preparation done in order to achieve the right
staining surface. Although
there are several methods of stain removal, i.e., sand blasting, chemical
stripping, just to name a couple, we recommend corn media blasting as
the best overall method. It is effective, non-toxic, quick, less destructive
to the wood than sand, and you won’t have to worry about interior
water damage from blasting your home with water under pressure. We rent
a corncob media-blasting machine called the Kernel. As
with any blasting process, the media will find its way into your home,
so be aware that you will have to do some interior clean up of the dust
and the media itself. Although corn blasting doesn’t generally leave
as textured a surface as sand blasting, some people prefer a smooth log
surface, so you may have to do some light follow-up sanding by hand. Sand
blasting can be too aggressive on wood creating an undesirable surface
texture. It typically takes someone very experienced to avoid this problem.
Sand blasting can severely etch glass, so you must mask all windows before
attempting to blast your home. This is not the case with corn cob blasting.
Sandblasting generates air-borne dusts of silica, which can cause silicosis
– so it is important to make sure anyone near the blasting operation
wears proper respiratory protection. Once you have finished blasting,
then there is the significant clean up of the spent sand. Power
washing not only raises the grain, but can create long “fingers”
of wood fibers (called “felting”) that will generally have
to be sanded off once the wood has dried out. Water under pressure being
blasted against outside walls can find its way into your home. If you
must power wash, take necessary precautions to protect the interior of
your home: remove wall hangings, pull furniture away from the exterior
walls, have towels handy for drying wall and floor surfaces. After you’ve
power washed, you must wait for the logs to dry before applying any stain.
You may miss out on a window of good weather opportunity while you are
waiting for the logs to dry out. [Note: Virtually all of these problems
are non- existent with corn cob media blasting.] The
“open time” of High Sierra is longer than that of Capture,
helping to prevent lap marks when brushing. Capture is more flexible than
High Sierra, it does not penetrate into the wood as much, which is by
design. Capture is top-coated with clear Cascade, which can be used as
a maintenance coat a few times over the years to make such early maintenance
relatively easier than re-applying pigmented High Sierra. In conclusion,
the two stains are created through the use of significantly different
polymers, which gives each product its’ own appearance. One
heavy coat of Capture is recommended; followed by one
coat of Cascade. If the product is applied heavily it can build sufficient
film thickness to protect the wood and provide several years of good performance.
If one coat is applied that is too thin, less durability will be the result,
and more frequent recoating will be required. Cascade
should not be applied by itself, unless re-coating over Capture stain.
Cascade has additives to prevent attack from ultraviolet light, but these
additives are not nearly as efficient in protecting the wood surface as
the pigments we add to Capture stain. No,
Cascade does not absolutely have to be used over Capture – but it
is a very good idea. Capture remains relatively tacky because the polymers
in the stain are very rubbery in an effort to handle the movement of the
logs. Cascade dries to a harder finish and reduces the pick up of dirt
and dust on the logs. Also, when Cascade is applied over Capture, it brings
out the “depth” of the stain, enhancing the grain of the wood
and providing a soft luster that is very attractive. Finally, if a reapplication
of clear Cascade is done 2-3 years after the initial application, then
the overall stain system can be bolstered, both aesthetically and in endurance.
Eventually, just reapplying more Cascade will no longer be sufficient,
and at that point more colored Capture stain will be required. Yes,
both products may be used on the interior. Sashco suggests top-coating
both High Sierra and Capture with Symphony to enhance the appearance and
give the protection you need on the interior of your home. Generally, loss of gloss or variations in gloss may be an indication that another coat of Cascade should be applied to your home. An annual check of the moisture prone areas (i.e. low courses of logs) and upper curvature of your logs will often give you an indication that you need to re-coat. Wet the area in question, and if there is a color shift or an area where the water is drawn into the coating, it might be an indication another coat of Cascade is needed. Cascade can easily be applied with a garden sprayer, so an annual re-coat is not bad practice. 18.
Can I put Capture/Cascade over High
Sierra and vice versa? Symphony
is formulated to be compatible with both Log Jam, Log Builder and Conceal.
Other interior clear products may have additives that will cause problems
with adhesion of Sashco’s log sealants. Symphony is also formulated
to be more flexible than many interior clears to better handle the movement
that typically occurs in logs. Yes,
Symphony is tintable with universal colorants found in most paint stores.
Always test the color in a small, inconspicuous area of your home. It depends on the look you want for your logs. Normally, 2-3 coats of Symphony will give your logs both the look and protection you want. |
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