Spackle, putty and epoxy wood filler are products that if properly used, can repair and eliminate unsightly defects and blemishes before a coat of paint is applied. Some name brands of filler products include “Dap, Crawford’s, Elmer’s, Red Devil, Synkoloid, Evercoat, and Restor-it”.
Spackling Paste Conventional pre-mixed spackling paste, also referred to as spackle is heavy paste filler typically consisting of calcium carbonate and chemical binders. It can be used on wood, drywall, and plaster to conveniently fill holes up to ½ inches deep, small cracks, and other minor surface defects. Because spackle has a tendency to shrink, it is best to overfill the damaged areas. Once the paste has completely dried, it can be sanded to a smooth even surface. Two or more applications are usually necessary for voids deeper than ¼ inch. Spackling paste is designated for interior use, exterior use, or interior/exterior use.
Even though the term “spackle” was originally a trademarked name, it has become synonymous with all types of spackling paste.
Spackle - Dry Mix
Spackle also comes in powder form and requires mixing with water to make a paste. You should only mix the amount of material you need to complete the drywall spackling at hand. The dry mix has an advantage over the ready mixed products insofar as it can be stored for a longer time.
Lightweight Spackle is made from Sodium Silicate Glass (liquid glass) and low shrinkage chemical binders. It is primarily used to fill small holes and voids up to ¾ inches on drywall and plaster. It can also be used as wood and masonry filler for certain applications. This material has different working characteristics than traditional spackling paste. Because lightweight spackle has the ability to limit shrinkage, it will outperform traditional spackle for holes deeper than ¼ inch. Then again, lightweight spackle does not sand easily or function well as a surfacing compound, compared to traditional spackling paste. Therefore it should be applied flush with the surface profile of the substrate.
Painter’s putty is pre-mixed, ready to use, wood filler typically consisting of ingredients such as ground limestone, calcium carbonate, linseed oil, and titanium dioxide. It is well suited for interior and exterior use on new or previously painted wood to fill nail holes, small cracks, and other minor voids. Because of its dough like consistency, painter’s putty is not readily sand-able and does not function well as a surfacing compound.
Painter’s putty should be allowed to dry to the extent that the surface has skinned over before a coat of paint is applied. Sometimes the linseed oil in the putty can bleed through, causing the subsequent paint coats to flash. Spot priming may be needed.
Oil Glazing Putty
Oil glazing putty is used to secure and seal glass panes typically found on older style, wood and steel window sashes (frames) and doors. Newer windows and doors rarely use glazing putty as a sealant. Oil glazing putty is a type of linseed oil putty similar to painter’s putty, but with slightly different working characteristics. Once the putty is properly kneaded, it can be manipulated more easily than painter’s putty, especially on larger areas such as the perimeter of a glass pane.
Water putty is an all purpose, plaster base compound suitable for filling larger holes, voids, and cracks. It is available in powder form and requires mixing with water to make a paste. Because of the rapid dry time, you should only mix the amount of material you can use in 5 to 10 minutes. Drying times may vary depending upon the manufacturer.
Some positive attributes of water putty include good adhesion, no shrinkage, and a hard consistency that can be sculpted into a detailed profile. Water putty can be sanded with coarse sandpaper although sanding is somewhat difficult. It is best not to overfill holes and voids so as to avoid unnecessary sanding or grinding.
Polyester filler is an interior/exterior, two-part catalyzed putty consisting of a fill paste and a cream hardener additive. Because polyester filler offers good adhesion, easy sanding, and low shrinkage, it works well for several wood and metal fill applications. It can be used as a surfacing compound to fill shallow scratches, under-filled nail holes, and other minor imperfections. It performs well to fill larger holes and gouges. Polyester filler can also be used to repair defects, such as broken and dented corners on wood trim. Upon drying, it can be sanded to match the surrounding profile of the substrate.
Polyester filler will not properly dry unless the two components, filler paste and cream hardener are mixed together. A 50:1 mixing ratio is typical for many two part polyester fillers. Always check the manufacturer’s directions before mixing. The catalyzed material will dry within a few minutes, so only mix a small amount of material to optimize workability and avoid waste.
Clear Penetrating Epoxy Sealer (CPES)
Clear penetrating epoxy sealer is a two-part catalyzed liquid formulated to penetrate into wood. It works especially well for dry-rot repairs. It can also be used as a wood pre-conditioner before painting. Upon drying, CPES hardens within the pores of the wood helping to reinforce and strengthen the surrounding wood fibers. Epoxy sealer consists of two components, parts A and B. They must be mixed together with the proper mixing ratio specified by the product manufacturer.
After mixing, the epoxy sealer should be generously applied to the entire surface of the damaged areas until the wood is fully saturated. Allow the liquid sealer to dry overnight before applying the epoxy wood filler.
Epoxy Wood Filler
Epoxy wood filler is a two-part, catalyzed fill paste that is well suited for large voids, such as is often the case with dry-rot repairs. Some attributes of epoxy fillers include high strength, negligible shrinkage, and good adhesion. Epoxy wood filler can be sanded and sculpted although sanding is somewhat difficult. During application it is best not to overfill, so as to avoid unnecessary sanding or grinding.
Epoxy wood filler consists of two components, parts A and B. The two parts must be thoroughly mixed together so that the fill paste can properly harden. Using two separate putty knives, place the proper ratio of each component on a flat surface. Fold the two parts together and repeat the process until the mix has a uniform color.
Always refer to the manufacturer’s directions for the proper mixing ratio as it may vary among different epoxy wood filler products. Many brands use a 1:1 mixing ratio. Epoxy wood filler will dry within a few minutes, so only mix the amount of material that can be readily used so as to optimize workability and avoid waste.