Wipe-on polyurethane

Overview

Wipe-on polyurethane is polyurethane supplied thin enough to rub on with a lint-free cloth. Wikipedia's comparison table calls oil-based polyurethane "easy when thinned and wiped on". Minwax sells ready-made oil-based and water-based Wipe-On Poly versions, and says it gives a hand-rubbed look while protecting against water, household chemicals, food stains and wear (maker claim). General Finishes' Arm-R-Seal is an oil-based urethane applied thinly with the excess wiped off, which GF's data describes for brush or roller application.

Pros

• No brush marks, and a forgiving process: Minwax tells you to apply a liberal amount to a lint-free cloth and rub it in.
• Minwax gives a 2 hour recoat for both its oil-based and water-based Wipe-On Poly.
• Water-based version has low odor and water cleanup (Minwax).
• Thin coats can be built in as many layers as you want.

Cons

• Thin film: each coat adds little, so protection comes from layers. Minwax recommends 2 coats; Arm-R-Seal uses 3.
• The oil-based can carries a fire warning for rags and waste (see Safety).
• Streaking can occur: GF notes that semi-gloss or gloss are easier to wipe on than satin.
• Not for exterior use on these products: Minwax lists both Wipe-On Poly versions as interior.
• Coverage is stated per pint on the oil-based can (62 sq ft per pint, maker data), so large surfaces use a fair amount of product.

Suitability

Suited to interior furniture, chair parts, small tables and trim on Red oak, White oak, Hard maple and Hickory, where you want a low-gloss, close-to-the-wood look. The water-based Minwax version suits pale work because it dries clear (maker claim); the oil-based versions warm the wood. For heavy-use surfaces, a brushed Oil-based polyurethane or Water-based polyurethane puts on more film per coat.

Coats and application

Prepare the surface (Sanding schedule). Minwax directions: stir, apply a liberal amount to a lint-free cloth and rub it in; allow about 2 hours (2 to 3 hours dry, then lightly sand with 220 for the oil-based); apply a second coat; allow 24 hours before light use. GF Arm-R-Seal: apply thinly, then wipe off the excess; sand between coats with 320 or finer, or 0000 steel wool (never steel wool on water-based finishes); 3 coats; recoat after 24+ hours. See Wipe-on application for technique, and Rubbing out a finish after full cure.

Compatibility

• GF: let oil-based finishes dry 72+ hours before applying water-based over them; let water-based dry 24+ hours before applying oil-based over them.
• Over oil-based stains, wait for the stain to dry and follow the can (Oil-based pigment stain).
• GF says Arm-R-Seal ambers, so do not use it over light or white finishes.
• Do not use water-based products over linseed or Danish oils (GF).
• Do not apply lacquer over polyurethane (Minwax brushing lacquer label).

Care and repair

Clean with a damp cloth. Because the film is thin, renewing it by scuffing and wiping on another coat is the usual repair; test on scrap first. Wikipedia notes oil-based polyurethane can be stripped with paint remover.

Safety and environment

Minwax's oil-based Wipe-On Poly label carries the DANGER warning that rags, steel wool and other waste soaked with the product may spontaneously catch fire; place them in a sealed, water-filled metal container (Oily rag safety). Wipe-on products put the finish on a rag with a large surface area, so this matters here. Cleanup uses a regionally compliant cleaner per Minwax. GF's Arm-R-Seal label is flagged combustible and Prop 65. The federal VOC limit for varnishes is 450 g/L (40 CFR 59); GF lists Arm-R-Seal VOC for gloss at under 528 g/L, so check your state's rules. No food-contact claim is made here; see Food-safe finishes.

Related

• Oil-based polyurethane: brushed equivalent
• Water-based polyurethane: brushed waterborne
• Wipe-on application: technique
• Oily rag safety: disposal of rags
• Tung oil, Boiled and raw linseed oil: oil finishes also applied by rag