I just finished installing furring strips in the dressing area and had a terrible time. I have a steel framed aluminum skinned trailer and all the studs that i attached the furrings to are steel tubing except for the ceiling supports. Well I pre drilled with a smaller drill for #10 stainless metal screws and the heads of the screws were braking off. I went to a slightly larger bit and some of the screws would strip and not seat. At first I used counter sink flat head screws and when I ranout I ended up having to buy a box pan heads because thats all they had left. Had to counter bore each hole so their head would not protrude however they held better .
I realize that once everything is tied in together with the panneling it should be stronger but I'm concerened about having some of these screws break off from road vibration and bumps.
What are your thoughts?
Posted 2009-06-26 11:30 PM (#107124 - in reply to #107121) Subject: RE: DIY
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Posts: 25
Location: Sedalia, Colorado
Originally written by sidelock on 2009-06-26 10:05 PM
I just finished installing furring strips in the dressing area and had a terrible time... Well I pre drilled with a smaller drill for #10 stainless metal screws and the heads of the screws were braking off...
Were you using self tapping screws? I have had good luck with these with hex type heads by predrilling and setting them by hand. If you need flush mount countersink the firring strip.
Posted 2009-06-27 1:09 AM (#107128 - in reply to #107121) Subject: RE: DIY
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Location: North Carolina
Sounds like you used sheet metal screws instead of the self tappers. (self tappers have a thread cutter built into the screw) But I think the wood strips will allow the trailer to flex without breaking the screws.
Posted 2009-06-27 7:50 AM (#107132 - in reply to #107121) Subject: RE: DIY
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Posts: 720
By nature, the stainless in the screws is very brittle- hence the breaking. As OP said, likely not a problem. But, with extended use and particularly a lot of vibration I could forsee breaking several. I'm thinking that while a pain, while I can still readily access them I might give thought to backing them out individually and replacing with a regular steel version.
Posted 2009-06-27 9:37 AM (#107142 - in reply to #107132) Subject: RE: DIY
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Location: Sedalia, Colorado
Originally written by horsey1 on 2009-06-27 6:50 AM
...I'm thinking that while a pain, while I can still readily access them I might give thought to backing them out individually and replacing with a regular steel version.
Probably best to do so.
Use self tappers, predrill size to just accept the initial cutting portion, and set by hand. Sometimes a hand drill driving the screw will have to much torque at the end of the set and will break or strip.
Posted 2009-06-27 10:06 AM (#107144 - in reply to #107121) Subject: RE: DIY
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Posts: 70
Location: Temecula, CA
Chances are the screws you used will be fine. They were breaking because the holes were smaller then the screw thread it self and steel doesn't give like softer metals. The screws that you already put in that didn't break will be ok. A few might break off due to the trailer flexing but this would happen no matter what screw you used.
Posted 2009-06-28 7:13 AM (#107179 - in reply to #107121) Subject: RE: DIY
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Posts: 117
Location: Toronto ontario canada
Picked up a box of #10 " SELF DRILLIG " hardened steel hex head / pan heads and used as recomanded ,a 9/64 drill bit for pilot holes. Holy buck fatman these screws are the cats ass, You can hang a horse off these things.
Wish I'd known this before !
Still debating weather or not to replace all the other 200 odd screws or just go around and add a few of these in between for security.
Just thought I'd post this information and save others the headache !
Posted 2009-06-29 8:56 AM (#107224 - in reply to #107121) Subject: RE: DIY
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Location: western PA
The sheet metal screws were designed for sheet metal, which is usually thin and is somewhat pliable. The screw tip penetrates a small pilot hole, the tapered shank enlarges the hole, and the coarse threads cut into the metal and pull it to the head. If you unscrew an installed sheet metal screw, you will see the fastened metal is misshapen and deformed at the area under the screw head.
When this screw is installed in a thicker metal, the coarse and wide threads cannot cut and bend the heavier materials. It binds and any excessive torque shears the head or shaft. If the pilot hole size is increased, sometimes the screw can be used, depending on the hardness and thickness of the metal.
A hex head hardened screw has a fine threaded body with cutting flutes and some even have a self drilling head capability. The shanks are straight and the threads are meant to cut into the metal, threading itself into the material. The threads are shallower, lessening the necessary torque for installation, but more numerous for the proper grip. The hex head design allows a higher applied torque with a socket, than the open screw slots for the installation.
Any screw you have used is stronger than the wood you have fastened. The amount of vibration in your LQ is nominal, and any minute activity will be absorbed by the weaker material which is the wood. The area under the screw heads will deform with the movement. It would take a severe lateral motion to effect enough change to shear your installed screws.
Posted 2009-06-29 10:28 PM (#107318 - in reply to #107121) Subject: RE: DIY
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Location: Toronto ontario canada
That makes sense Gard. I was at the trailer today and layed the plywood in the gooseneck floor . I took a good look and tugged on the firring strips and came to the logical conclusion to leave them as they are and not bother changing all the screws.