# Does stain stripper really work?



## Boden Painting (Dec 27, 2007)

I've been asked to bid on a project to refinish a large red cedar sided home. The home had been coated with Flood CWF-UV5 roughly 10 years ago.. On the sides of the home getting weather/exposure a lot of the Flood has deteriorated and is flaking off. The home owner would like the cedar to be brought back to as "new" as possible. There are spots on the home that have mold/algae and most of the soffits and areas that don't get much light are much darker then the other areas.

Does anyone have any experience with the flood stainstrip product? Is this the best route to remove the clearcoat before brightening? Any other words of wisdom or things to look out for?

thanks in advance


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## 4ThGeneration (Apr 17, 2007)

If its been 10 years it is most likely already weathered off, but I would still strip and pH balance to be safe.


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## NCPaint1 (Aug 6, 2009)

Sodium Hydroxide. Thats probably the best chemical for stripping stains. Read the jug on the stripper you use, it should be listed as an active ingredient ( regardless of the manufacturer ) look for that one.

Safe Strip from Gemini is another one that works well ( I sell it and have used a fair amount myself ) I cant remember the chemical in that one, only that its got like a 15 letter name. This one wont burn your skin, wont kill vegetation, and doesnt need to be neutralized. It needs to be mixed with water, using a higher concentration that whats recommended will do nothing other than waste material and $$$.


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## Retired (Jul 27, 2010)

There are basically three types of strippers the most basic (pun intended) is a Sodium Hydroxide aka lye type. Very old and very powerful. An old formula was water,flour and flake lye. Cheap too. A 50lb sack of flake lye from a chemical supplier is about a half a buck a pound if that. The chemical sales outfits in most cities have and sell by regulation USP grade which jacks the price up about tenfold for the lab grade product.

Methylene Chloride is the main hired gun in the solvents and paste strippers. Nasty stuff but it's not flammable and works great. Fine furniture stripping outfits use it straight or in fume chambers. Not for rookies or amateurs.

The citrus type strippers. OK if you have time to mess with them and need paint stripper to smell like an orange popscicle.

Sound like the stuff on that cedar clad place has about lived its life. If I were calling the shots my first choice would be a good power wash with a mild solution of bleach (sodium hypochlorite) and water pumped up with Jomax to kill off the grungy stuff on the north face and in the places where the sun don't shine. 

For more , just plug in the correct terms into a search engine. ie "Sodium Hydroxide+paint stripper".


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## PressurePros (May 6, 2007)

Any sodium hydroxide stripper would work but they are not created equal. They also must be followed with an acidic wash to neutralize and brigthen the wood.

A product I like is HD-80. You can mix the powder 10 oz per gallon in warm water and downstream for maximum efficiency. This is a professional grade product that requires the correct PPE. Its also must cheaper than anything you can buy from a paint store and will outperform it. 

http://www.theprosealerstore.com/HD80.htm

You will also need:
http://www.theprosealerstore.com/powersolve-dsi-brightener.htm

That is premixed and ready for downstreaming. There is also a powersolve stripper that is premixed and ready to use.


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## Retired (Jul 27, 2010)

The hydroxide strippers even when neutalized react with the tannins in the wood. They are not the thing to use on cedar. 

Many of the hydoxide base strippers do not work well below 70 degrees F. 

For the price of this suggested prorprietary stripper. It's worth a shot to try IMO.


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## NCPaint1 (Aug 6, 2009)

Water from powerwashing activates the tannins. Tannins are water soluble which is why waterborne primers typically don't work.


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## PressurePros (May 6, 2007)

I have restored over two million square feet of wood and perhaps 35% of that has been cedar. We have never had a problem with tannins when it comes to stripper. Tannins can affect choice of sealer. Redwood is the only wood that becomes an issue when choosing a sealer.


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## Retired (Jul 27, 2010)

From the Wolman/RPM site:

Sounds to me like the OP may need a couple of passes with different product types to pull this one off. 



*Q: What is tannin? Do I have to worry about it?*
*A: *Tannin is a natural extractive of Cedar, Redwood and most other dark woods. It migrates to the surface of the wood when water is present and leaves an ink-like, coffee colored stain or overall darkness on the wood after the water evaporates. Tannin bleeding is unsightly, but not damaging to wood or any coating on the surface. It can be removed with _WOLMAN Cedar & Redwood Deck & Fence Brightener_ or _All Exterior Wood Deck & Fence Brightener._ *DEFINITION: Tannin (or Extractive) Bleeding:* Redwood, Cedar and Douglas Fir are examples of wood species that contain naturally occurring, water soluble chemicals that tend to migrate to the surface with exposure to extracting agents such as water. After rain or heavy dew, coffee or tea-colored stains may appear on the wood surface. If the wood is coated, discoloration of the coating may occur when tannin extractives are dissolved into the coating solution by water, reach the surface and remain as dark, coffee-brown stains after the water evaporates. This reddish-brown bleeding is unsightly, but not damaging to the coating.


Another article that may save the OP time wading through the mine is bigger than yours advertising and sales pitches.

http://www.historichomeworks.com/hhw/library/coatings/cleanersandrestorers.html


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## Boden Painting (Dec 27, 2007)

thanks for the advice and links everyone.I'm going to try and peruse them tonight. 

I've already pushed this one off until spring..there wouldn't be enough time to do what needs to be done this fall. Perhaps I can try a few products on areas of the house and see what seems to work best. I'm guessing it's going to be a combo of stripper and revive/brightener, which ones is the problem. The HO has already tried the Flood product and was unhappy with the results, so he might be a bit biased already.

I already explained to the HO that what he expects and what he can reasonably expect may be different considering the age and deterioration of the product and wood.


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