Tek Screws are Horrible

[Canine]

I started using Tek screws to fasten the plywood to the bottom of my camper, but they broke. They do not work at all.

I need another way to fasten the tin onto the side of my metal camper frame. The tin is 1/4 inch Delta Rib. It will be installed horizontally. I will likely be working by myself outside.

With the nice weather, I'll be able to go to town Monday if I can figure out a way to fasten that tin and the roof. Am thinking VHB tape. Am also thinking LocTite PL 8X. I'm not sure I can get Sikaflex, at least the kind for metal to metal and if I do find it, it might be expired. Another option is 3M 5200.

Or whatever ideas you have. Thanks!

 

[speedhighway46]

Canine: how abt a couple of pics so we can get a clearer image of what you are doing and what you need. We I built my Peterbilt Motorhome I used several different styles of fasteners, including stainless steel 10x24; steel self-tapping, and aluminum rivets. All worked great for their specific application.

 

[sephson]

Have you thought about using a tap and die set? It's more work and you'll probably need to improvise a method of holding the tin in place while you drill and tap your first two holes.



Also, I've worked with a lot of different self tapping screws over the years. Some have been great, some have been absolute garbage. The worst were basically pig iron screws, sheared there heads off or snapped if I looked at them funny. You may just need better quality screws. I've had good luck with wafer head self drilling screws. They're available from a number of different suppliers, though I don't recall ever seeing them at Lowes or Home Depot.

 

[BradKW]

I use TEK fasteners with some frequency, as they are sold at HD and offer small quantities of certain specialized fasteners I would otherwise buy in bulk. I find they are acceptable quality and haven't had problems in general. From what you're saying, I would guess that the difficulty you're experiencing has to do with application of (I'm guessing) self-tapping/drilling screws. Here are a few issues I have had, perhaps they might relate:

1) Stainless steel fasteners are always soft and prone to breakage regardless of brand. Whether going into wood or metal, pre-drilling makes all the difference and the better you match drill to screw size the less chance of breaking.

2) Self tapping/drilling screws will often have on package "12ga to 20ga metal" or similar. This is often a bit of a lie as you approach the heavier gauges. Pre-drilling usually solves this.

3) When screws heat up they a more prone to breaking...and having to wait while it self-drills through 2 layers of metal can make this likely, heavier the gauge the more likely. Pre-drilling usually solves this.

4) Impact drivers can be less than ideal with certain self-tapping applications.

 

[Canine]

I was using an impact driver, but changed to a drill in an attempt to avoid breakage.

I tried drilling a pilot hole and that didn't help in the smallest way. Kept using bigger bits until the hole got too big, but they still snapped off.

I'm drilling into 1/8" square steel tubing and 3/32" angle iron.

A tap and die would work, but I would need to do a few hundred of them. Lotta work.

The camper is in a shop right now, so no pics today. The only pic on this site is the one under the Trucks sub forum. Just coated the floor. Since the plywood isn't tight with the camper, there are gaps for water to run in. That is such a bummer. Now I need to silicone it and hope it seals. Doing a custom build is much harder than I thought it would be. Seems like every step something comes up. Frustrating.

 

[SternWake]

Self drilling/tapping  screws through two layers of metal are pretty much guaranteed to be a screw breaker.

Put a stop collar on the drill bit to get screw through first layer of metal without having to self tap, let the screw to the tapping into the second layer.

If these are coarse threads, if they align with the thickness of the metal, it makes them easier to break as well.

Could try and lube the screw too.  At the minimum it will show you how hot it is getting.

 

[flying kurbmaster]

I think those tex screws like the ones for roofing are not meant to go into steel, wood thread, they are made for wood, sure they go through the thin roofing material but not for anything thicker, stainless screws usually number 10 with a Robertson bit. pre drill, screw it in, if you are running into problems a wax stick helps dip the tip of the screw into it then predrill and screw, or use pop rivets if your metal is tight onto the steel. hope that helps.

 

[BradKW]

Its also worth expanding on what gsfish said about how course the tread is. When screwing through thin metal, the metal actually "fits" between the threads as it goes in...if you're going into thick metal, such as 3/32", there's basically no self-tapper that will actually "thread" through it. When people are having success anchoring to van structure, what is actually happening is the threads are deforming through the thicker steel, wedging into a secure placement.

This is what tap and dye kits do, they actually create a thread pattern through thicker metal. This would also be an application for RivNuts, something like this: http://www.amazon.com/gp/product/B0...liid=I17KO10T6XEXWD&ref_=wl_it_dp_o_pd_nS_ttl

Ironically, its quite possible that contrary to this thread's title, the reason you're not having success is because TEK screws could be better quality that some self-tappers, and instead of allowing the treads to "smoosh", they wedge and thus snap off...thus weaker stainless screws might be an answer.

 

[Canine]

I got a chunk of scrap tubing and one size larger brand name Tek screws to practice with.

Am playing with the idea of using VHB tape. Maybe it won't work, but that's OK. I'm losing a great deal of my fear of having things not work correctly the first time. Am getting comfortable with trying something then being immediately prepared for a plan B.

 

[AngryVanMan]

This would also be an application for RivNuts, something like this: http://www.amazon.com/gp/product/B0...liid=I17KO10T6XEXWD&ref_=wl_it_dp_o_pd_nS_ttl

I cannot recommend these enough in place of self-tappers where possible, the stainless ones are just great for making well secured, yet removable panels for future servicing.  Very handy little inventions!