Installing battery tray advise

[HallOfDreams]

i have a 2004 340 and want to install 4 house batteries, that bit is easy but I am fearful of screwing into the bottom of the boat to mount the battery trays or clamps securely. Does anyone know how much meat there is so I don’t end up going through the bottom (eek!!) I see searay installed captive nuts in the hull bottom for screwing clamps to these are about 1/2” deep.
Thanks

 

[sbw1]

You could always secure them with 4200. Should hold them just fine and they will be removable if need be.

 

[HallOfDreams]

View attachment 75097 You could always secure them with 4200. Should hold them just fine and they will be removable if need be.

I did think if bonding was a option

 

[Creekwood]

I have a 1997 330 so not the same boat, but I installed a pair of 6v golf cart batteries as a house bank and installed them in a Blue Seas battery box that is screwed into the flat deck in the bilge. There are several things screwed into that deck on both sides (water heater, waste tank, etc) so I expect it is good to use. Here is a picture:

 

[HallOfDreams]

Got a reply from Searay support. They said they use 1” screws.