Exterior screws won't grab, tighten

[Guest]

Silicone spray will not harm the seals in most valves and is easier to use on a valve since it will flow easily.. When rebuilding them we were taught to coat things with white lithium during reassembly, keep in mind that this was not potable water though. I do use a white lithium on my water hoses and connections for my RV but we never drink that water. I dont think it will cause any harm on drinking water lines but it may produce a bad taste for a little while.

Keith,

Remove a small piece of foam from one of the cutouts in the floor and use this material to test compatibility. There is also food grade silicone spray from CRC that can be used.

Jim

[familytruckster4]

I have a question. I've seen recommendations in these instances for larger screws with "coarse" threads. Wouldn't "fine" threads hold better on thin sheet metal?

If its a combination of laminated materials such as luan and sheet metal or thin sheet metal then a regular sheet metal screw is best. If its into thick sheet metal then a finer thread cutting screw like a type F would grip better. https://www.valuefastener.com/thread...1075_1174.html

One of the problems with RV assembly is that there is very little time to finesse the screws, they drive them quickly because of time constraints. They also use a lot of drill point screws which do not produce as much grip as a regular sheet metal screw but it avoids the need for a hole to be drilled. They are especially bad when screwing two items together such as the plastic side fenders to the exterior. Because of the way the drill point screw grabs both materials there is little control over the grab on the outer surface making it difficult to control how hard the outer item clamps to the inner surface. Ideally the outer item would have a hole slightly larger than the diameter of the screw so that the panel would float until the screw was driven home. Unfortunately this process would take two extra steps of drilling the outer panel and inner panel with different size holes after the piece was mocked up and the hole locations were marked. Its a better way but much more time consuming.

[BillinTexas]

There is no foam in this area as it is the "attic" area. I got the screws replaced with larger screws. Camera works great.