rv7boy
Forum Peruser
Doug was very gracious in turning my email into a daily story on today's update of his web site. I feel compelled to share a little more of why silicone is considered such a bad guy in the adhesive bonding world. On the space shuttle solid rocket motor nozzles we use a lot of adhesives (some of them are very high tech) and contamination control is serious business. Even though our RV's are aluminum airplanes, anyone who is building or has built one knows that we do use a lot of adhesives, mainly epoxies and polysulfides.
Here's the gist of an employee bulletin board poster in our manufacturing area:
Bonding Alert: Silicone Awareness
Silicone (def'n): A Colorless, Odorless Oil That Is Used Widely Throughout Industry
If silicone gets on our bonding surfaces...One Drop Can Hurt a Lot!
>1/20th of a drop of silicone per square foot can cause up to 85% strength reduction in our bond systems.
>1/20th of a drop of silicone will easily fit on the head of a pin ...but the detrimental effects on our hardware could be disastrous.
>Silicone contamination can come from many sources: hand lotion, cosmetics, films, silicone sprays, etc.
The reason I am concerned about this is that I believe many builders may not be aware of how serious silicone contamination in the bonding world can be. Please understand that this is not intended to knock silicone. It has excellent lubricating properties, and there are probably several places we should use it on our RV's. Just be aware that when you are doing any adhesive bonding, do everything you can to keep silicone away. It is easily transferred from the skin to metal and composite parts.
I trust this adds to your "education and recreation" in building your RV.
Don Hull
Here's the gist of an employee bulletin board poster in our manufacturing area:
Bonding Alert: Silicone Awareness
Silicone (def'n): A Colorless, Odorless Oil That Is Used Widely Throughout Industry
If silicone gets on our bonding surfaces...One Drop Can Hurt a Lot!
>1/20th of a drop of silicone per square foot can cause up to 85% strength reduction in our bond systems.
>1/20th of a drop of silicone will easily fit on the head of a pin ...but the detrimental effects on our hardware could be disastrous.
>Silicone contamination can come from many sources: hand lotion, cosmetics, films, silicone sprays, etc.
The reason I am concerned about this is that I believe many builders may not be aware of how serious silicone contamination in the bonding world can be. Please understand that this is not intended to knock silicone. It has excellent lubricating properties, and there are probably several places we should use it on our RV's. Just be aware that when you are doing any adhesive bonding, do everything you can to keep silicone away. It is easily transferred from the skin to metal and composite parts.
I trust this adds to your "education and recreation" in building your RV.
Don Hull
