| p>Sodium Hydroxide, Sodium Percarbonate and | | | | Sodium Hypochlorite is chlorine found in typical |
| Sodium Hypochlorite are the three main cleaning | | | | household bleach. Used as a disinfectant and sanitizer, |
| agents used in deck and log home restoration. Each | | | | it is excellent in removing and killing mold and mildew. |
| chemical has its place in the cleaning process, | | | | It does little however in removing dirt and other |
| however, knowing when and how to use each one is | | | | contaminants. |
| often misunderstood. | | | | Many homeowners and some less informed |
| Sodium Hydroxide, the strongest of the three, can | | | | contractors use bleach to clean decks and other |
| be used either as a mild cleaner or when mixed | | | | wood surfaces. |
| properly, an aggressive stripping agent. Sold over the | | | | There are a few things that need to be considered |
| counter, it is one of the main ingredients found in | | | | when using this method for cleaning wood. |
| oven cleaners, dish washing liquid, stain removers, | | | | Most importantly, chlorine bleach (Sodium |
| degreasers and deck cleaners as well as a host of | | | | Hypochlorite) is one of the main chemical compounds |
| other products. City municipalities even use it in the | | | | used in paper mills to brake down the wood fibers in |
| purification process of drinking water. | | | | the paper manufacturing process. Chlorine |
| In deck and log home restoration it is used to | | | | disintegrates the lignin in the wood which is the glue |
| remove mildew, grayed out wood fibers and oil | | | | that holds the wood fibers together. Once the lignin is |
| based stains and sealers. With proper dilution it can | | | | removed the fibers are reduced to a pulp that then |
| be applied to the wood preferably by spraying but | | | | is extruded through a series of rollers that expels the |
| also can be brushed on. It is very important to note | | | | water and leaves a paper substance after it dries. |
| that proper safety measures be taken when using | | | | The point is that too strong of a chlorine mixture can |
| this method and all instructions should be closely | | | | destroy the wood fibers in the deck or log home. |
| followed. Never mix water into Sodium Hydroxide. | | | | If bleach is poured onto a piece of wood and allowed |
| Instead, always mix the chemical into the water | | | | to dwell any length of time, you can take a stick and |
| slowly and carefully. Mixing water to the chemical first | | | | actually scrape away a significant layer of the wood. |
| causes a reaction that produces an enormous | | | | If you examine it, you will find that it has turned the |
| amount of heat and fumes. Safety goggles and | | | | wood to pulp. Not only does this destroy the wood, |
| gloves are mandatory as well as other protective | | | | but it is almost impossible to rinse all of the bleach |
| clothing. Also, this chemical will kill grass and plants as | | | | from the wood. If you put bleach on your fingers |
| well as stain glass, siding and other surfaces. If you | | | | and try to rinse it off, you will find that it is very |
| are not sure about how to use this product, it is | | | | slippery and very hard to remove it from your |
| strongly recommended to find a professional who | | | | fingers. This indicates a high ph level. The same thing |
| does. This is nothing to play with. | | | | is true with the wood. So there ends up being a |
| If there is no sealer on the deck or if only traces | | | | bleach or stripper residue left on and in the wood. |
| remain, a mild solution of Sodium Hydroxide and a | | | | Not the ideal situation to be applying a new finish. |
| good surfactant can be applied and allowed to dwell | | | | Since these chemicals are hard to completely rinse |
| for a predetermined length of time. This allows the | | | | from the wood even after copious amounts of rinse |
| mixture to soften up the surface contaminants and | | | | water, the wood will still have a high ph level. To |
| degraded wood. A scratch test can be preformed to | | | | counter this, the wood has to be neutralized to lower |
| determine how easily the deck will clean up. If it is | | | | the ph level in order to stop any damage to the |
| hard to remove, either more mixture will have to be | | | | wood and also keep from interfering with the new |
| applied and/or more dwell time allowed. If it is | | | | finish. To do this Oxalic Acid is used. Applied by |
| determined to be at a point that it can be removed, | | | | sprayer, the acid lowers the ph level of the wood |
| then a pressure washer will be used to remove a | | | | and at the same time brightens the wood. This |
| very thin layer of the degraded wood and any stain | | | | process whether intentional or not, is often |
| or other contaminants such as mildew, grill grease, | | | | overlooked by the homeowner as well as the |
| flower pot stains, etc. | | | | uninformed painter during the deck or log home |
| Care must be taken when using a pressure washer. | | | | restoration process leaving residual amounts of |
| If someone is not familiar with using a pressure | | | | chemical in the wood. Again, not the ideal situation to |
| washer, irreversible damage to the wood can occur | | | | be applying a new finish. |
| causing costly replacement of decking boards or | | | | Also, chlorine by itself does little for cleaning dirt and |
| handrails. Actually, less than 1000 psi / of pressure is | | | | other contaminants. Therefore a detergent must be |
| needed. Water pressure is not as important as water | | | | added. TSP (trisodium phosphate) is a good cleaning |
| volume. The more water, the more cleaning and | | | | agent if mixed properly. TSP is a derivative of borax |
| rinsing power. At the very least, 4gpm is needed to | | | | and care must be taken when applying to any |
| properly remove the unwanted material. This rules | | | | surface. Be sure to never let it dry on glass or |
| out most homeowner type pressure washers which | | | | certain metals. |
| usually rate less than 3gpm (gallons per minute.) | | | | Chlorine does have its place in the cleaning process. |
| Sodium Percarbonate is the same chemical found in | | | | Mixed properly and applied sparingly, it is the best |
| the popular "Oxy Clean" products advertised on | | | | method of not just removing mold, mildew and algae, |
| television. A non-chlorine cleaner, it is a good choice | | | | but also killing the mildew spores deep into the wood |
| as a deck cleaner when a less aggressive cleaning or | | | | cells. Used properly, chlorine can do an excellent job |
| stripping is needed. Although it may remove some | | | | without damaging the wood, but it must be used |
| stain residue that may be left intact, it is better | | | | correctly and must be neutralized to achieve good |
| suited for the removal of mildew, dirt, light grease | | | | results without damaging the wood. |
| spots and gray, degraded wood. It will not harm | | | | Remember, the key to a long lasting stain is properly |
| grass or most surfaces if properly rinsed. | | | | cleaned and dry wood. Anything that will interfere |
| It is mixed to a predetermined solution depending on | | | | with the performance of the sealer; existing stains, |
| the severity of the job, allowed to dwell and | | | | dirt, mildew, chemical residue or moisture must be |
| removed with a pressure washer as with the Sodium | | | | completely removed using one of the cleaning |
| Hydroxide. With this product it is advised to only mix | | | | methods, neutralized with an acid bath and allowed to |
| what can be used in a couple of hours as it looses it | | | | dry. Dry is defined as moisture content of at least |
| cleaning power. | | | | 15% or lower. Anything higher and the oil stain will |
| This is a good, less aggressive cleaner that can be | | | | not absorb properly into the wood. And the more |
| used where there may be delicate plants and flowers | | | | stain absorbed into the wood, the better the |
| in the area or animals in close proximity. Safer for the | | | | performance of the finish. Remember, preparation |
| homeowner to use than that of the more aggressive | | | | and more importantly, proper preparation, is the key |
| strippers, it will clean the wood well enough that a | | | | to a good and lasting finish. |
| sealer can be reapplied with decent results. | | | | |