Back in time when hot water machines were just starting out in this field, the people who had them used the knowledge that hot water cleaned better than cold water. This was a selling point to get the contract. The people who did not have a hot water machine and could not afford to buy one started coming up with negative theories to enhance their cold water machines and reasons why to use them instead of the hot water machines. Throughout the years many of these theories have gone by the wayside. About the only one remaining today is the one about hot water doing damage to wood.
There has been no tests or studies made, that I know of, on hot water Vs cold
water cleaning. There have been tests and studies conducted concerning the use of high
pressure steam and the damaging effects it has to wood. I believe that this is why the last remaining myth about hot water damaging wood is staying around so long. There is a big difference between hot water and high pressure steam.
Here are a few things that we have found concerning the use of hot water:
#1. Chemicals mix better in hot water. #2. Strippers work better and faster when mixed with hot water. Most manufactures of strippers will tell you that heat will activate the stripper faster, therefor requiring less dwell time. #3. Hot water cleans better, therefore requiring less pressure to be used. ( Less pressure means less damage to the wood.)
As for the felting of the wood substrate. There are numerous reasons on what
causes felting. #1. The type of stripper used, #2. bleach. #3. Pressure at point of contact.#4. Condition of wood before pressure washing. #5. Is the product that is on, holding the moisture in the wood causing a soft substrate? Anyone of these factors along with a few other conditions can cause felting. We have stripped and cleaned many, many decks and homes with both hot and cold water. Some felt, some don’t, some felt more than others. If the wood substrate is going to felt, it won’t make any difference if you use hot or coldwater. In all our jobs, defelting is a normal step in our procedure.
The choice of the two machines is up to you to decide. Keep in mind that a hot
water machine can also be use as a cold water machine. To change a gold water machine
to a hot water unite, you’ll have to buy a hot box, so where is your saving?
Jim Bilyeu
Exterior Woodcare
<FONT COLOR="#000080" SIZE="1" FACE="Verdana, Arial">[This message has been edited by Jim Bilyeu on July 16, 2000 ]</font>