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Historic Preservation - Technical Procedures

Spectitle:
Preparing A Non-Toxic Water-Repellent Preservative

Procedure code:
0631001S

Source:
Developed For Hspg (Nps - Sero)

Division:
Wood And Plastics

Section:
Preservative Treatment

Last Modified:
02/24/2012

Details:
Preparing A Non-Toxic Water-Repellent Preservative



PREPARING A NON-TOXIC WATER-REPELLENT PRESERVATIVE


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on preparing a non-toxic
         water-repellent preservative.  It is a formula provided
         by the United States Department of Agric= ulture Forest
         Products Laboratory.


PART 2---PRODUCTS

2.01 MANUFACTURERS

    A.   United States Department of Agriculture
         Forest Products Laboratory
         P.O. Box 5130
         Madison, WI  53705
         608/231-9200

2.02 MATERIALS

    NOTE:  Chemical products are sometimes sold under a common
    name.  This usually means that the substance is not as pure as
    the same chemical sold under its chemical name.  The grade of
    purity of common name substances, however, is usually adequa= te
    for stain removal work, and these products should be purchas= ed
    when available, as they tend to be less expensive.  Com= mon
    names are indicated below by an asterisk (*).

    A.   Mineral spirits:  

         NOTE:  MINERAL SPIRITS SHALL BE CLEAN AND COLORLESS SO
         THAT IT WILL NOT ADVERSELY AFFECT THE TEXTURE OR
         DURABILITY OF THE STAIN.

         1.   A petroleum distillate that is used especially as a
              paint or varnish thinner.=

         2.   Other chemical or common names include Benzine*
              (not Benzene); Naphtha*; Petroleum spirits*;
              Solvent naphtha*.

         3.   Potential Hazards:  TOXIC AND FLAMMABLE.

         4.   Safety Precautions:

              a.   AVOID REPEATED OR PROLONGED SKIN CONTACT.

              b.   ALWAYS wear rubber gloves when handling
                   miner= al spirits.

              c.   If any chemical is splashed onto the skin,
                   wash immediately with soap and water.

         5.   Available from construction specialties
              distributor, hardware store, paint store, or
              printer's supply distribu= tor.

    B.   Paraffin wax

    C.   Boiled linseed oil:  

         1.   Boiled linseed oil shall be used rather than raw
              linseed oil as raw linseed oil does not dry.  

         2.   The linseed oil shall be clean and colorless so
              that it will not adversely affect the texture or
              durability of the paint.  

    D.   Clean, clear water

2.02 EQUIPMENT

    A.   Double boiler

    B.   Stiff bristle brush

PART 3---EXECUTION

3.01 ERECTION, INSTALLATION, APPLICATION

    NOTE:  THIS WILL MAKE 5 GALLONS OF SOLUTION.

    A.   Melt (1 lb.) paraffin in double boiler being caref= ul not
         to get it too hot as it can ignite.  Temperature should
         range between 80 and 100 degrees F.

    B.   Allow to cool to about 70=F8 F before adding the          preservative.

         CAUTION:  FUMES ARE HIGHLY TOXIC; WEAR PROTECTIVE
         CLOTHING INCLUDING GOGGLES; WORK OUTSIDE; USE ORGANIC
         VAPOR RESPIRATOR.

    C.   Add (3 gallons) boiled linseed oil and (1 gallon) mineral
         spirits, or whatever resin and solvent is being used.

    D.   Apply the mixture at 70=F8 to 80=F8 F.  Below 40=F8 F the
         paraffin is not sufficiently liquid and the  material
         cannot penetrate.  Above 80=F8 F the mixture dries too fast
         and will not achieve sufficient penetrat= ion.

                         END OF SECTION