THE USE OF WOOD CONSOLIDANTS AND FILLERS IN THE HISTORIC RESTORATION PROCESS

By Lynn, Statewide Field Services Representative

This article will focus on one of several systems manufactured to aid in the restoration of historic wooden objects.  Specifically, it will focus on products manufactured by the Abatron Corporation and their use in the restoration of historic wooden window sashes.  Although I have used other products, I was first introduced to the Abatron system in the early 1990s and therefore, am most familiar with them.

Wood consolidants and fillers have been determined acceptable by the Department of Interior and the National Park Service for use when restoring historic wooden objects to a useable condition.  Many of these systems are user friendly as with the Abatron products.  For example, frequently historic wooden window sashes exhibit rotting stiles and rails.  Replacing wooden parts with newly milled material is not only costly, but takes the project out of the hands of most people except those of the skilled woodworker.  It also requires the sashes being taken offsite.  However, wood restoration systems make it possible for the average homeowner or craftsperson to make many of the repairs themselves.

Different items by Abatron

Lynn demonstrating how to use one of the Abatron products.

In the case with Abatron products, the consolidant (LiquidWood) is a two part viscous material that when mixed in equal parts and applied to rotted and decaying wood, reinforces, rebuilds, and waterproofs the offending material.  It is the first step in the restoration process and is applied before the wood filler.  Once the consolidant becomes tacky, the wood filler can be applied.

The filler (WoodEpox) is also a two part system but comes in a two color dough form.  The dough is a high-strength, no-shrink structural adhesive putty.  Once again, equal parts are mixed to form a uniform substance that can be used to fill even large holes, cracks, and rotted areas.  To smooth the dough, one only need dip the putty knife in some isopropyl alcohol and carefully work the material.  Once the dough has set, it can be sanded, shaped, and routed.  It can also be tinted with dry pigments when combining the two parts, and stained, or primed and painted afterward.

It is important to remember two things; the consolidant goes a long way, so only mix a small amount at a time.  In addition, the working time for the wood dough is only about twenty minutes, so only mix up an amount that can be worked in that timeframe to avoid waste.  It is also important to remember that since the WoodEpox generates heat as it cures, the larger the mass, the quicker it cures due to the amount of heat generated and trapped within the mass.  Thus, thin applications will take longer to cure.

When used correctly, wood consolidants and filler can produce a very professional end result.  In addition, these products allow the homeowner greater autonomy in the hands-on restoration process.  It is true that certain situations will require wood replacement, but the Abatron process allows for many jobs that might otherwise be sent out to be completed on site and at a greatly reduced cost.  Visit the Abatron website at Abatron.com.  Give it a try and good luck!

If you would like to learn more about historic wooden window rehabilitation, contact Lynn at [email protected] to set up a workshop.  You can also visit our website for more information on why to save historic windows.