attaching plate to bed.

[house]

I hope is ok to start another topic about this, but I am just about to attach the floor plate to my cross members and I was planning on using 8, 1/2 bolts to bolt them down 1 on each corner and 2 more near the center like 28 inches from the edge.  I figure if i make is so you can unbolt the plates which are basically 4x8 it will make it easy if i need to ever work on anything to access it from the top.

 

This past weekend I had to use the truck and before I got a chance to get the attachments done so i just strapped the 5/16 sheets to the cross members and it sounded a like someone was beating on a metal drum as i was driving down the freeway, so now i am concerned that it is going to be like that once the plate is bolted down. is there any better way to put the plate on? 

i were to put some double sided tape on the cross members it would help quiet it? should i just weld it?  I would love to hear your thoughts and experiences.

Edited August 6, 2019 by house
grammer

[rickeieio]

I gots my nomex undies on, so I'm prepared for some disagreement............

I prefer more, but smaller bolts.  That helps reduce the metal drum effect.   But, I have to ask, will there be anchors or tie down points added?  Will they be bolted through the cross members too?  I used 3/8" bolts on my removeable sections.  I welded nuts under the cross members.  I plan to swap out the hex heads for button head stainless at some point, just to reduce trip hazard.

[house]

I used tubing for my cross members, so my plan was to use nuts and bolts along with some unistrut 90s welded to the tubing. like these

https://www.unistrut.us/product-details/p6026

Totally open to doing something else, i just figure more bigger bolts is less work for me.  

[rickeieio]

I would still weld the nuts, becuase it can be a PITA reaching under the dirty bed to hold them.  I made that misteak the first time around.

If you are not relying on the floor as anchor points, then it's simple to use smaller bolts.  Heck, 1/4" would be fine.  I'm no enjinear, but I would think it would be silly to use bolts bigger than the floor thickness, unless you use big fender washers to spread loads.

[Alie&Jim's Carrilite]

Going to bring up a name or 2 here...

Carl, Suite Success and Denver and Judy Geity (SP) both have panels that are held on by 1/4-20 button head bolts.  Carl has his removable panels along the driveshaft area to make service easy.

[Randyretired]

My removable panels are held on with 1/4" 20 bolts.  The nuts are welded on underneath.  These are just part of the bed and do not have anything tied to them.  One of the panels is fairly big and somewhat heavy so I drilled 2 holes and welded nuts so I can bolt on a handle to pick it up with.  I have removed these panels to work on a some things and I am sure glad they are there.  These are quiet.

[Darryl&Rita]

Our deck plate is 1/4" checker-plate steel, held down with 4 1/2" bolts. The bottom of the plate is gusseted with angle and square tubing. to match the carrying capacity of the deck itself. It's probably overbuilt, but I'd rather that than underbuilt. The bolts are recessed into pipe sleeves, to remove any tripping hazard. The nuts are welded in place.

[SuiteSuccess]

Here is a pic of what Jim was referring to. The center panels (2) are the undercarriage access.