So let me start at the beginning... My annual bonus will be coming in soon, so I'll have about $1000 to blow on mods. First on the list is an onboard air system. The air system will power air horns, air bags in the rear, and a quick disconnect valve in the bed that I can use to inflate tires, snow tubes, etc.

Hurdle #1 is mounting the air tank. I have decided to mount it under the truck to one of the frame rails (to keep the truck bed clear and stock-looking). It will mounted under the gap between the truck bed and cab in order to clear all the suspension parts.

The tank will be attached to the rail with some heavy duty "L" brackets. My first instinct is to drill holes and use nuts/bolts, since that's what some aftermarket trailer hitches do. However, I'm somewhat squeamish about drilling holes in my frame... Option B is to find a shop, and pay them to weld the brackets to the frame, and then bolt the tank to the brackets.

Does anyone have any experience or insight into the safety aspects of drilling holes in the frame rails?

The tank will weight 10-15 pounds, so it needs to be a pretty heavy duty mount.

 

look under the truck now and see how many random holes are in the frame from the factory

a few mounting holes for a tank and/or pump is not going to harm a thing

 

I wouldn't do it. There is extensive design engineering done on those frames to locate holes where the least amount of stress is located. If you put a hole in one of the highest areas of stress, you could be putting a stress concentration (failure point) right in the middle of it.

Trying to find a way to use one of the existing holes somewhere would be your best bet.

What about using some straps similar to how most fuel tanks are mounted? You could protect the frame from the tank and straps with some sort of plastic or something.

 

Drill your holes in the frame. If you drill the frame and take the time to thread the holes for the bolts you plan to use, any weakness would be reinforced once the bolt is threaded in. You can always put a washer and nut on the back side of the frame to reinforce and lock the bolts in place.
Welding will cause the frame to rust and is permanent unless you do a lot of cutting and grinding. I doubt any hole you drill and fill with a bolt will weaken the frame with any significance. JMO

 

yeah I'd definitely drill and tap the holes and just thread the mounting bolts into the frame rather than just drilling a threw-hole and putting a bolt and nut on it (which might be difficult anyway since it's a fully boxed frame)

 

I recommend you dont do it. Just from my understanding of how a frame works and my years of experience wrking on airframes of helicopters I know altering the frame is not a good idea. I assume it is the same with this truck. And a bult will not make up for what you have taken out it will not be completely secure and you could cause hairline cracks in the frame. We do something called NDI (Non-Destructive Inspection) i think thats what it means but anyway its pretty much a sonar that we use to check for cracks in metal unseen to the human eye whenever we have to alter an airframe due to battle damage or hard landings. I recommend you do not unless you want to rivet it in place and make sure whoever does the drilling has some experience. It seems simple enough but you never know. Plus despite what some may think the frame does move and part of the engineering and crossmembers is to enforce it when it does. Now if you add something in the middle and the frame does tweak a little or something it may snap something you installed or damage the frame. I would recommend trying to construct a type of clamp with runbber grips so it has some play that you can mount over the frame rails and then maybe mount the tank to those so no frame drilling will be needed and you can remove it if you wish in the future

 

I wouldnt drill hose, use existing hose if your can.
Or weld brackets on and paint a rust preventive like POR15 over them.

 

hose=holes?

 

I have no idea if this will fit on the F150 somewhere, but it is interesting:
http://www.chassisgrabber.com/index.html

 

Sorry for misspelling