various questions- flooring

[blindpony]

We've recently bought an old Crown, and are currently removing the floor due to rot issues. I had planned on laying down a layer of 3/4 " plywood and then putting fir flooring over the top of that. In the demolition process, i've discovered that there is some type of 1/2" asphalt backed fiberboard that is sandwiched in between the top layer of 3/4' ply and the bottom layer of 3/8" ply. This was all screwed to metal struts at various intervals- no metal floor except around the wheel wells. I'm wondering about the purpose and and importance of this fiberboard- sound and/or heat insulation? Could this material be much more effective than the same thickness of plywood and solid fir? An important consideration is that the engine is in the middle of the bus underneath the floor, so sound deadening seems fairly important...
Another item i am unsure of is the undercoating on the bottom layer of plywood. I had thought of doing an epoxy coat on the bottoms and sides of the underlayment plywood, at least around the wheel wells. Is this overkill? Is there a cheaper exterior paint that would be appropriate?
-lastly, everything in our bus is fastened with an annoying breed of safety screw-the head is like a many pointed gear, and the auto parts store sells no bit to to drive them. We've been removing them with vise grips, a laborious and sometimes ineffective process, as they strip easily. Is there some specialty bit available? I sure hope so.

[blindpony]

unfortunately no. The points are on the outside of the head- some sort of socket would be necessary to drive them. I don't have a camera or i'd post a picture of them.

[baadpuppy]

Does it look like this?



If so, that would be a reverse torx.

hope this helps,
jim

PS, saw my first one of those bolts in person just this week, on a hard drive assembly. Immediately strikes the eye as "that's just wrong".

[Sojakai]

I dont know, I think those Micro-Torx screws are pretty wrong... But then again I like taking apart dead harddrives for the discs inside. They make great dinner bells/windchimes.

[baadpuppy]

Originally Posted by Sojakai

I dont know, I think those Micro-Torx screws are pretty wrong... But then again I like taking apart dead harddrives for the discs inside. They make great dinner bells/windchimes.

At the risk of serious thread drift...

I do the same thing. Mom loves the platters. We also keep the monster magnets out of them. With a steel structure bus, those could come in handy. And those tiny little torx are a PITA.

As for the reverse torx, I saw in my google image search that some people are selling those tools. I might just have to get some myself. You never know when you'll need some esoteric tool like that.

jim

[Sojakai]

Can you score the head and use a flat-head screwdriver?

Its what I have to do for those Micro-Torx screws... What size bit are those?!