What length screws should i use to mount equipment inside my boat?

[adell50]

1973 27' Catalina

I have a shore radio, mic bracket, gps, accent block..all that I need to attach to the inside of the boat in various places. Obvisiously, different places on the hull are thicker than the next, however does anyone have advice on a general rule of thumb on what to use?

Many thanks!

[Harborless]

Well it is hard to have a rule of thumb since boats are built so different depending on times, sizes, ect.
Says you have a 1973 27' Catalina. They used to make them a bit thicker back then- I would expect you have between 1/2" and 3/4" fiberglass above the waterline. or mounting equitment you only need to go deep enough to bed it in tight unless you are talking about bolting through the hull- I dont get the impression you are.
A rule of thumb? Be very careful with any screws over 3/4" in length unless your sure you have the depth to work with.

[deniseO30]

Assuming most everything you will be installing is going to be attached to the hull liner, or cabinetry, go short as 1/2" # 6 or #4 for light duty attachments. Thick based things like paper towel holders may call for a longer screw.

[JimsCAL]

You don't want to just screw into solid fiberglass. First it's probably too thin and secondly it won't hold well. In those situations, epoxy a wood block to the hull and then screw into that.

[Siamese]

Don't be puttin' screws in your hull.

There are plenty of other places in your boat to mount things. Generally, the length of screw is determined by the thickness of the material you're going into. No sense in the screw exceeding the thickness of the material.

It's nice when you can find at least a half inch of wood to go into.

Often, the best choice is not a screw, but a nut and bolt...and a lockwasher, assuming there's a way to get at both sides of the material you're going into.

Use stainless.

[smackdaddy]

+1 on no screwing into your hull! Do like Jims says above and epoxy wood anchor blocks onto the hull surface - then screw into those.

My C27 doesn't have a thick hull AWL. I definitely wouldn't screw into it.

[brak]

Yep, one more vote for wooden epoxied (or otherwise glued) anchor blocks. Your boat will thank you.

[T37Chef]

Originally Posted by JimsCAL

You don't want to just screw into solid fiberglass. First it's probably too thin and secondly it won't hold well. In those situations, epoxy a wood block to the hull and then screw into that.

I would 2nd, or 3rd , or whatever its up to JimsCal suggestion!