Thread: Best screws to prevent rust
2nd May 2009, 02:34 PM #1
- Join Date
- May 2009
I've had a read of "Skeletons under your van floor?" thread and decided to check out my van. I made all the ply lining myself over a year ago.
I used drywall screws to fix the ply to the van. In the floor area the screws penetrate the van floor and are exposed to the elements outside.
Now I never bothered to treat the exposed screws (I bought the bloody Hamerite and all but never used it ).
I took out a few screws to check them. They have some rust on the surface. They are the black drywall screws from B&Q (Like this http://www.screwfix.com/sfd/i/cat/02/p1221702_m.jpg). I was told these are the guys for the job from someone who has done a lot of van conversions.
I cannot see any rust on the underside of the van. I'd have to take up the floor (sealant and all) to have a proper look.
A friend suggested remove the screws, drill slightly larger holes (to drill out any potential rust), replace with non-rust screws, treat with Hammerite. A sound plan?
Non-rust screws - what is the best kind? I understood these drywall screws have a protective coating. Should I try to get stainless steel screws?
Would drilling larger holes be beneficial?
Is Hammerite the best way to coat the screw after, should I also Hammerite the drilled holes?
I'd like to nip any rust before its a problem.
2nd May 2009, 03:05 PM #2
Stainless steel is best.
Bright Zinc Plated (BZP) is pretty good so long as the plating holds out.
Brass can be used for light duty.
Black oxidised (or 'self-colour' ) are to be avoided.
Here to share the love.
2nd May 2009, 05:24 PM #3
Yep go with the stainless or brass options. Any salt that gets in will always be damp (its hygroscopic) so there is always good contact for any corrosion to take place.
And steel screws rust like a good'un with salt - especially if you temporarily use them for your footstraps and then completely forgot you'd put them there. What numpty would do that?
2nd May 2009, 06:07 PM #4
Or outdoor decking screws. Although you may have trouble finding them in a short enough length.This space is kept clear for random notes, reminders, or a shopping list.
4th May 2009, 04:30 PM #5
Originally Posted by basher
- Join Date
- Feb 2007
I'm in the process of replacing eyebolts and eyescrews (for bungee and rope tiedowns) in my van. Most of this hardware is 4-5 years old (not stainless). Any of the pieces near the board and sail storage are now showing considerable rot...I should have spent the extra money for stainless in the first place.
5th May 2009, 04:01 PM #6
- Join Date
- May 2004
Stainless is the only way to go but the floor of your van is still mild steel and needs some protection where there is an open edge/drilled hole. You won't need to increase the hole width/screw size if you get the right size stainless screws. Beware as stainless screw heads can be a bit prone to shearing if you overtightent then or try to force a large screw into a small hole.
Best thing for these holes as they have already been contaminated is a bit of Ku Rust - rust killer, it oxidizes the rust turning it black, then apply a layer of zinc paint - paint or spray on. Then a top coat of something that is a bit tougher like an polyurethane multi purpose paint - the polyurethane means it won't chip if hit by bits of stone chip etc. It'll last for years then.