I'm stripping latex off my second story deck (8×38). I've stripped approximately a 12×8' section using 2 gal of Jomax Stain & Finish Deck Stripper. (This should have been enough to do 200 sqft instead of 90) While it says it will remove latex finishes, this product isn't exactly made to remove paint – but it has worked, slowly – dwell times of 1-2 hours instead of 15 minutes. It is also $20 per gal and I'd need 6 or 7 gals to complete the surface.
Since this, and most deck finish and paint strippers, are just Lye (Sodium Hydroxide) and a surfactant, what would a recommended ratio be to make my own solution? 1-2 oz lye to 1 gal – Stronger?
What surfactant – Tri-sodium phosphate? Dawn?
I'll whip something up tomorrow one way or another, so any pointers is appreciated.
I'll be neutralizing with oxalic acid.
I'm open to other recommendations for stripping that does not involve sanding or scraping.
[Of course, eye, skin, hearing, and respiratory protection will be worn throughout… ;)]
Best Answer
I found my answer - pasted below for completeness.
Homespun Paint Stripper Mixing your own.
By The OHJ Technical Staff Old House Journal
Well before today's sea of commercial chemical- and solvent-based paint removers flooded the market, folks set on stripping mixed up their own. This caustic-type stripper is concocted to taste from common ingredients that cost next-to-nothing.
In a non-metallic container, such as a joint-compound bucket, gradually dissolve lye in 2 gallons of warm water. Start with a medium-strength solution Ñ say 2oz. lye per gallon of water. Test for effectiveness, then increase concentration if desired. Make a pasty stripper by mixing corn starch and water in another bucket. When the water is milky, slowly blend it into the lye solution.
Apply with a tampico-bristle (whitewash) brush; the stripper is particularly practical for removing paint on masonry. However, like all caustic strippers, this mix is highly basic and will darken some hardwoods. Test first in an inconspicuous area and rinse the surface thoroughly before repainting. Most important, work carefully while mixing and applying the stripper. Wear eye protection and rubber gloves, making sure to rinse skin immediately if it comes in contact with stripper.
Edit: I attempted mixing this as strong as 1 lb Lye: 1 gal water and letting it sit for more than 3 hours (while reapplying frequently) Still no luck on my deck. Back to finding a commercial solution