• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Self tapping screws an rust prevention

Share this page

catfood

catfood

Jedi Knight
Country flag
Offline
In a few weeks time I should have a nice shiney new body for my car and as part of the rebuild process I will no doubt be using self tapping screws to secure the wiring harness and trim panels etc. In order to avoid rusting of the screw holes what do you guys do? Two techniques I've heard used are dipping the screws in waxoil or wrapping them in plumbers tape. Any other methods folks use?
 
Steve--

Naturally you will want to use stainless steel screws so that they themselves do not rust. If, as I think, you mean rust to the bodywork where the hole is drilled, I doubt that oil or tape would do any good as either would be worked off when the fastener is run in and thus would provide little or no protection to the bare metal edge. The best you can probably do is dab paint around each fastener after it is tightened--both inside and out.
 
I agee with Michael :

Just be sure and take your magnet along with you as these days of imported stainless products are not like our previous USA made hardware. If they cling to the magnet for dear life, they are heavily mixed with steel and are not good stainless. OK
 
Spot of silicone caulk on each hole before you put screw in . Keeps my hardtop on boat waterproof when I installed antennas, radar etc. Get your ss screws form a marine shop.
 
Had not thought about this. If this is an issue, the car likely experiences very humid conditions. If that is the case, rust will find its way into many other places as well. Rust just is not much of a problem in inland areas of low humidity where cars are only driven in summer.
 
I've had problems dismantling the car with corrosion around the existing self tappers. Its difficult to tell if it rust is from the screw or the steel the screws are screwed into. I want to make sure I cover all bases in preventing the problem in future.

Cheers
 
Maybe a 'topical' application of one of the waxy rust preventatives? I've had good results with LPS3, some have recommended a 'better' one I can't recall the name of and, of course, Waxoyl should work as well.

Some aircraft are treated by fogging a thin rust preventative into cavities (like wings). One indication of a successful treatment is the preventative oozing out from under rivet and screw heads. Since a Healey chassis is hollow this would work well, if only there was a way to fog all the chassis parts.
 
I have always squeezed some Loctite antisieze into the holes that I would drill into the fender or quarter panel when installing mud flaps on my cars and then use stainless self-tapping screws to mount the mud flaps. Never had any problems with rust despite all the water and salt that collects around these areas of the car.
 
catfood said:
As a matter of interest what size self tappers are used for the wiring looms?
Click to expand...

I've taken original looms off both a BN2 and BJ8. In both cases none of the screws are what I'd call 'self-tapping;' they were all 'regular' sheet metal screws--requiring pre-drilled holes--with Posidriv heads. I believe they were #8 size, usually half-inch long.
 
Back
Top