Backing blocks for seacocks

cdawgs65 · Post by **cdawgs65** » Tue Jul 10, 2007 11:04 am

Is there a standard thickness for backing blocks, if so what is it, I have some pieces of mahogony plywood 3/4" that I want to use, it's for my Pearson Triton 559, thanks

Post by **dasein668** » Tue Jul 10, 2007 12:27 pm

I don't think there's a "standard" thickness. I used 3/4 ply for my seacock backing plates. Some materials (such as manufactured fiberglass panels) can be thinner than others.

cdawgs65 · Post by **cdawgs65** » Wed Jul 11, 2007 8:15 pm

Thanks for the reply, I kinda figured but just wanted to be reassured, like your website,

JonnyBoats · Post by **JonnyBoats** » Thu Jul 12, 2007 12:06 pm

This may have been answered before, but does Starboard make good backing blocks?

Rachel · Post by **Rachel** » Thu Jul 12, 2007 12:09 pm

I would say "no," for at least two reasons:

1) It is very resistant to things (such as caulking) sticking to it.

2) It is subject to "creep" when under load.

Rachel

Ceasar Choppy · Post by **Ceasar Choppy** » Thu Jul 12, 2007 12:15 pm

[Edit: Rachel beat me to it....]

NO! Search for a thread a few months ago about starboard to get the skinny.

1. nothing sticks well to starboard (i.e. caulk) especially epoxy or polyester/vinylester.
2. the rate of expansion and contraction of the pastic will invite leaks

Good wood (marine ply, teak, etc.) can be used if well coated with epoxy. The epoxy seals out the moisture which could cause wood to expand,

FRP (see Rachel's Downsizing a TH thread: ) works well too.http://triton381.com/forum/viewtopic.php?t=2256

Maine Sail · Post by **Maine Sail** » Thu Jul 12, 2007 10:51 pm

I simply laminated a 5/8 inch thick piece of fiberglass on a waxed piece of glass and then cut holes with my hole saw and glassed them to the hull.

Glassing my backing plates to the hull!

Nice and Solid!

Ready to be installed with Sikaflex!

Plastic Classic Forum

Backing blocks for seacocks

Backing blocks for seacocks

Backing blocks,

I used fiberglass