Drilling into the A frame

[er78mph]

Hello and thanks all in advance.

I am mounting a pair of 6V batteries to the top of the trailer tongue and was wondering if I could drill two 1/4 screws? The batteries wont fit on the intended spot without the box and I would like to keep it away from the elements. Would it be ok to keep the batteries exposed with the wiring? I actually drilled into the A frame already but stopped after the first hole because I didn't do any research? Initially I thought it drilling would be fine but I started to second guess myself. I just want to drill the box into the A frame and then use straps. Any suggestions? Thanks, again.

[myredracer]

aguablanco wrote:
Just a quick question. Don't the manufacturers weld the battery angles and propane mounts to the a frame? If it was such a bad idea I don't think it would be a standard practice for as long as it has been done. Just wondering.
RichH

That's the first thing that came to my mind. TTs typically come with angle iron welded to the underside of the A-frame and they use thin angle iron, not the usual 1/8" stuff sold everywhere. If welding to the side of an A-frame, you are only supposed to make vertical welds. Not sure why. If installing angle iron to the top of an A-frame, the connection is not weight-bearing and nowhere near as critical compared to welding it to the underside.

Propane tank trays are thin sheet metal and are screwed in place (#8?). If you consider all the large dia. holes that get drilled into the side of A-frames for Reese dual cam brackets, friction sway bars, ground lugs and sometimes snap-up brackets, a couple of little 1/4" screw holes are nothing. Using self-tapping screws for the new angle iron is probably a better choice so you can remove or relocate it in the future if needed.

[westend]

Drilling two 1/4" holes in the trailer's tongue frame, especially if later filled by a bolt, is not going to change the integrity of the tongue frame 1 percent. I would bet that tacking on a cross piece to support other things would have the same result, near zero. With welding, I would think it impossible to take any temper out of the steel to the point where it weakens the frame to the point of failure.
But what do I know, I've done this many times with zero failures. Perhaps, more modern trailers have some type or configuration of steel that I haven't seen. All the ones I've played with have a full box steel frame.

[SoundGuy]

PackerBacker wrote:
Just use high speed/temp drill bits; start really small and work bigger with larger bits.

jackquontee wrote:
Thanks for that bit of information. I have now tried twice to drill into the frame on two different campers (the second time just this past weekend) and all it resulted in was a "walking" effect on the bit, and I ended up ruining two of the bits. Couldn't figure out what the problem was.

Trailer A frames are soft steel so I've never had an issue drilling holes using high speed titanium drill bits. Heck, dealer techs regularly drill large holes in the A frame to mount sway control and some models of weight distribution so there's no way a few small holes for mounting battery boxes are going to have any impact on the integrity of the frame at all. I personally have always used clamp on WD brackets but likewise have had no concern about a drilling a few small holes for mounting various items on the trailer tongue. Recently I moved my propane tanks to the rear of the A frame, then installed diamond plate as a tongue platform to which I mounted my battery box and Fresh Water Transfer Pump box, all of which required a few small holes being drilled in the A frame ... but that was much simpler than cutting and welding, especially since I don't own a welder and wouldn't know what to do with one even if I did. :W

[jackquontee]

PackerBacker wrote:
Just use high speed/temp drill bits; start really small and work bigger with larger bits.

Thanks for that bit of information. I have now tried twice to drill into the frame on two different campers (the second time just this past weekend) and all it resulted in was a "walking" effect on the bit, and I ended up ruining two of the bits. Couldn't figure out what the problem was.

[aguablanco]

Just a quick question. Don't the manufacturers weld the battery angles and propane mounts to the a frame? If it was such a bad idea I don't think it would be a standard practice for as long as it has been done. Just wondering.
RichH

[Grit_dog]

Roy b. That's cool! Slick setup and like you said, if the atv deck isn't loaded heavy then your batteries are a lightweight addition.

[DSDP_Don]

"er78mph"....."RoyB" has the best idea and cleanest setup with sufficient support for batteries. Go to Home Depot or Lowes and buy enough 1" angle to span across your tongue. Rather than drill 1/4" holes, buy four (4) large self tapping screws and screw both pieces of angle iron down at each end. Use some smaller self tapping screws with large fender washers to secure the battery boxes to the rails.

Once done, spray the steel and screws with some gloss black paint and you'll have a nice battery rack. You can also buy some aluminum diamond plate at HD and Lowes and cut a piece that fits between the rails and make it look really nice by trimming it at an angle that matches the "A" frame. You can rivet it on or use the self tapping screws.

If you want to get fancy, you can buy some plastic coated cable at HD or Lowes and make some cable locks.

[Community Alumni]

I've drilled into the frame on mine to install new propane line hangers. Just use high speed/temp drill bits; start really small and work bigger with larger bits.

[WNYBob]

If welded improperly you can weaken the steel also. A "U" bolts probably the best bet.

[RoyB]

GRITDOG - My OFF-ROAD POPUP trailer stays out for some good long trips sometimes and it's Amateur Radio and COUNTY WX ALERTs not NASA haha... I can pull 20-22AMPS DC Current off my batteries for a pretty long time frame before dropping them to their 50% charge state... Then I fire up up the 2KW generator to re-charge them in a quick three hour generator run time using on-board smart mode charging.

My OFF-ROAD POPUP trailer has six-inch x two-inch A-FRAMES and it weighs in around 4200 lbs when loaded up... It was built to haul around ATV machine on the front deck so a few batteries is still less than what one of those things weighs...

Roy Ken

[Grit_dog]

Btw, a couple small holes in the top flanges of the trailer tongue frame pales by comparison to the load applied by a steel truck box and hundred of lbs of batteries.

[Grit_dog]

Holy carp, that thing is all batteries!
Generator or a decent charging circuit from your alternator would be a more effective and less costly solution imo.
You running NASA ops out of your OFF ROAD POP UP?

[Grit_dog]

Like stated, prolly won't hurt to pop a couple small holes in it. You'd be drilling in the top flange which is typically in compression except when the trailer bucks over a bump, but that stress is going to be less than the constant tension stress on the bottom flange from the trailer loading. Plus the flanges are doing more for lateral stability and direct tension on the frame than holding up the weight of the trailer. The web provides most of the vertical strength.
Top flange, best place to reduce the section (drilling a hole), neutral axis of the web next, bottom flange next, top of web next, bottom of web worst spot. In general of course, without having calced the stresses and designed the beam.

[RoyB]

I added two right angle metal strips to the top of my A-Frame between the Propane Tanks and the Trailer wall.

This is what my three batteries looks like sitting inside the angle strips... I bolted the battery cases to my angle strips in lieu of the strap you mentioned


When I added four batteries to my battery bank I replaced those angles with longer units so I could mount my four battery cases which the two outside batteries extend out some over both sides. I could have just added longer strips on top of the ones I added but decided to go ahead and replace them.

This also allowed me to drill most of my holes into the added angle strip with only one bolt into the top of the A-FRAME.

I thought about welding these on but of course the large amount of heat might do more structure damage then drilling...

I'm glad I didn't weld anything as things keep changing. I am now wanting to install one of those 48-inch Truck Side mount boxes to install four Trojan T105 6V batteries in to go across my A-FRAME so I add some security from thief for my batteries...



Roy Ken