After watching a bottle jack punch through the plywood I had under it, on a sandy shoulder, just as I was getting the first nut back on, I resolved not to put myself into that situation again. I don't think I've ever hand spun three nuts into place that quickly.
For one. I'll never use plywood again under a jack. For another I found the jack to be less stable than I wanted it to be under the rear axle.
So I now carry a Powerbuilt Alltrade 640912:
https://www.tractorsupply.com/tsc/pr...ll-in-one-jack
I've used it once on the road since, and it's been fine. My van is under 8500 lbs ready to camp and I'm only lifting one corner with it.
It's a bit large to carry, but I feel much more confident about it than I did about the bottle jack.
If I hand't found that unit, I would have welded a cradle to the top of my bottle jack and started carrying a metal plate to put under it.