Do I need to weather seal nutserts? (mounting stuff to Ambulance exterior)

[Alloy]

I don't think anyone was talking about aluminum inserts or body material, the vast majority of riv-nuts used in automotive applications are plated steel going into sheet steel, and as I said above for installing inserts like that I would use body seam sealer to wet install those... for the third time, my recommendation for ultra gray was for bolt threads..

My Apologies.

 

[Bikersmurf]

On an aluminum bodied ambulance I’d lean towards aluminum nut-certz... I’ve bought & used them before. I’d keep in mind what I’m mounting and ensure that they’d be at least 3 times as strong as what would be required... standard Ambulance overkill

In general the joint created riv-nuts/nut-certz get tighter and stronger the more tension is on the bolt... until the point of failure. For anything structural in nature, I’d drill and tap into the 1/8” sheet aluminum over the 1/4” thick x 2” square tube structure that surrounds/is the ambulance box. The box is incredibly strong.... just watch one barrel roll yet have fully operational doors.

 

[Len.Barron]

Right, Plusnuts are definitely more secure. You just have to accept the giant lump surrounding the threaded hole. Rivnuts set deeper so are nearly flush.

I haven't bought any Plusnuts/T-Nuts yet but they look like they'd be well suited to many van/camper applications. I'd guess (given the "prebulbed" ) design you'd have a larger install hole vs same size rivnut and like you mentioned if you have interference on the back side the larger foot print could be an issue. I think I'm going to buy a pack of them and see what I think, I'm thinking they would be much better for installations in softer material like fiberglass, the larger grip footprint on the backside would be a big advantage for that (not that you shouldn't try and get a metal back plate in those installations if possible...but it's not always possible).
It's probably one of those things where having some of both is a good idea.

 

[iggi]

Installed my solar panels using the nutserts over the weekend. Globbed a big pile of urethane into the hole before installing the nutcert.
Feels super solid. Side note, it's good to have mounts with a little bit of flex in them. I was teeny bit off center on drilling some of the holes but the z mounts flex enough that it wasn't an issue.

 

[turbodiesel]

urethane sealant has worked pretty well for me.