Hey VernM,
I checked 3M sealants. I don't think this is what you meant:
http://solutions.3mindia.co.in/wps/portal/3M/en_IN/3M-ESPE-Asia/dental-professionals/products/category/preventive/clinpro-sealant/Just kidding.
Looks like these are the top candidates:
http://solutions.3m.com/wps/portal/3M/en_US/Car/Care/Products/Product-Catalog/Pages/?nid=69CBWNSM1PgsMDCVJW7L8SglLJK1KSX54Tblhttp://solutions.3m.com/wps/portal/3M/en_US/3MAutomotive/Aftermarket/Products/Product-Catalog/?PC_7_RJH9U5230GE3E02LECFTDQCEK3_nid=GSTN405H5ZgsXB20NJQ19WglLTDM7BX7QTblhttp://solutions.3m.com/wps/portal/3M/en_US/3MAutomotive/Aftermarket/Products/Product-Catalog/?PC_7_RJH9U5230GE3E02LECFTDQCEK3_nid=GS90WQG57HgsXB20NJQ19WglZR84HR8BGZblHey Pepperoni,
I didn't know about the hole plugs. Live and learn. In this case there was also a rust issue so I did the grinder->wire brush->rust preventer->bondo->primer->paint route.
I've seen the toilet seat + plastic combo. That might be a little too basic for me.
Hey Landyacht318,
I know the 15 amp charger will take a while but since I'm usually a weekend camper it will have most of the week to recharge the batteries. That should be enough time. Also keeping the van as a 15 amp system simplifies things.
The batteries will be stored in a vented box directly behind the drivers seat.
Here's the reason for the welding.
After removing the rear cargo mat and padding found this underneath.
There are four large bolts that secure the van to the under frame.
The rearmost set of bolts, a couple of feet from the back doors, shows bubbling under the paint.
Like this:

After grinding off the paint and chipping at the rust underneath you have this:

Way too much for a simple Bondo patch.