Underskinning question

[bighermHK45]

So I decided to underskin my 2 tube pontoon. I am purchasing .040 aluminum sheets (same stuff the dirt track racers use on their cars). I am going to get stainless steel 3/4" self tappers to attach the aluminum to the cross members. My question is, do I need to drill holes in the crossmembers or will the self tappers have enough bite to drill into them?

Any practical experience would be appreciated.

 

[HotTommy]

In my experience, stainless steel screws tend to snap more easily than regular steel screws, and they are much harder to remove after they snap. I took the extra step of drilling pilot holes in my sheets and crossmembers before letting the self tapping screws finish the job. I would rather drill 20 holes is soft aluminum than have to struggle with one snapped SS screw.

 

[bighermHK45]

Good to know. I will take the time and drill the pilots. Thanks for the input.

 

[ahicks]

Most later model battery powered drills do double duty as screw guns. Many (most?) are set up with a clutch type arrangement that can be set to a predetermined point where they slip/buzz when a predetermined amount of torque has been reached. You should be able to drive those self drilling/taping/TEK screws all day long, without breaking one, if, you just take a minute with some scrap material to set that clutch up so it lets go prior to breaking the screw.

 

[bighermHK45]

Gotcha. I will try a couple test runs.

 

[bighermHK45]

Most later model battery powered drills do double duty as screw guns. Many (most?) are set up with a clutch type arrangement that can be set to a predetermined point where they slip/buzz when a predetermined amount of torque has been reached. You should be able to drive those self drilling/taping/TEK screws all day long, without breaking one, if, you just take a minute with some scrap material to set that clutch up so it lets go prior to breaking the screw.

No pilot holes necessary. I am 3/4 the way thru the skinning and no issues so far.

 

[Bamaman1]

If you're buying the stainless steel hardware locally (Lowes or Home Depot), it's going to be very expensive.

I'd buy a kit from Pontoonstuff.com if I was doing such a job.

 

[bighermHK45]

Finish my underskinning project last night. I used #12 1" long Tek screws and didn't have any issues. I didn't need to drill pilot holes. I used about 190 screws, it may be overkill but the .040 aluminum is not rigid and I was afraid I was going to have a lot vibration issues if I didn't secure it tight to the crossmembers. The stainless steel screws were expensive. 2 bags of 100 each cost me $48 dollars at Fastenal. The project cost me approximately $330 in materials.

I will take the 'toon out today and see how the aluminum handles the water spray and chop that I will endure based on today's lake weather.

 

[BrianMc]

Since we're promoting other sites on here again. Check ebay next time. Fastenal is darn handy for when you need it now,but are always very pricey. Do use them at work in a pinch.