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

iggi

Ian
Hey all,

Got a few different things I want to mount to the body of my ambulance. (solar panels, rack, ladder, table bracket, etc.
Some of these things might get moved so I'm hesitant to go the adhesive route.
Nutserts seem the best way but I'm not sure if I need to worry about weather sealing them.
Some of them will see a lot of weather, standing snow, etc.

Pointers? Advice?

Thanks!
 

vintageracer

To Infinity and Beyond!
A little sealer around the Nutsert before installation is a good idea for an exterior perforation and certainly can't hurt anything.
 

Martyn

Supporting Sponsor, Overland Certified OC0018
Finding inserts with a seal isn’t an easy thing to do in North America, they are available in Europe but not so much here. The insert should seal well if it’s put in correctly, and as said a little silicon helps. Try using some neoprene on what ever you are attaching to the inserts, this will compress between the insert and the attached item forming a good water and dust seal.
 

luthj

Engineer In Residence
Just put sealant underneath the object to be bolted and then on top of the bolt head. This will prevent water ingress. I would avoid silicones. Nothing will adhere to cured silicone even more silicone. Stick with a good urethane such as Dicor Sikaflex etc.
 

J!m

Active member
Check McMaster-Carr for Viton washers. Find the ideal size (or even o-rings) and slide them on the nutsert before pushing it into the (close fitting- get a letter or number drill if you need to) hole.

Once you compress it, not much will get in. I am assuming you will use closed bottom nutserts. Paint the drilled hole and let it dry before inserting- even in aluminum. And finally, use a drop of never sieze on the bolt going into the insert, even if you have no plans to remove it.
 

iggi

Ian
Thanks for all the helpful advice! Probably start with installing my solar panels in the next couple days.
 

Len.Barron

Observer
put a light coat of body seam sealer on the exterior of the nutsert/rivnut before you install it to give a "wet installation" that's a common aircraft sheet metal technique. Coat the mating surfaces and all your threaded fasteners with something light Ultra Gray RTV as you are installing them...it will seal it up well and you will still (with a little extra effort) be able to disassemble them.
 

Len.Barron

Observer
No. Do NOT use silicone.
there's always that one silicone hater out there...just because it doesn't resist or inhibit corrosion doesn't mean it causes it.. if you are more comfortable with a polyurethane or polysulfide based sealant for everything then please proceed.
 

Alloy

Active member
there's always that one silicone hater out there...just because it doesn't resist or inhibit corrosion doesn't mean it causes it.. if you are more comfortable with a polyurethane or polysulfide based sealant for everything then please proceed.
In my experience silicone has very specific uses but if it doesn't bond the clean up needed to apply another type of caulking is PITA so I stay away from silicone unless it is an application that I've seen it used before.
 

Len.Barron

Observer
In my experience silicone has very specific uses but if it doesn't bond the clean up needed to apply another type of caulking is PITA so I stay away from silicone unless it is an application that I've seen it used before.
no argument with that...my reference to it was for coating fastener threads and mating side of flat washers/flanges where it's compressed/sandwiched; it works well for that and still allows the fastener to be removed without a lot of extra effort.
 

tk3

New member


Don't know anything about sealing but these links talk about what might be a better rivnut alternative.

Sent from my SM-N960U using Tapatalk
 

Alloy

Active member
no argument with that...my reference to it was for coating fastener threads and mating side of flat washers/flanges where it's compressed/sandwiched; it works well for that and still allows the fastener to be removed without a lot of extra effort.
I wouldn't use silicone for this....definitely not if the body or inserts are aluminum.
 

Len.Barron

Observer
definitely not if the body or inserts are aluminum.
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..
 
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