Through hull fittings - How much "play/distance" is ok?

[Terra Nova]

Originally Posted by Fuss

i agree that 2mm of play should be ok...

That example is not 2 mm of play, but 4 mm.

[skipmac]

Originally Posted by Terra Nova

That example is not 2 mm of play, but 4 mm.

4mm total but if the through hull is more or less centered it will be 2 mm all around.

[Sailorbob8599]

I'm truly surprised! One would have thought Hallberg-Rassey of all manufacturers, would have installed the correct fittings in the correct diameter holes, but maybe they are no better than the general run of manufacturers when it comes to getting it done right.
The OP does admit he is a "newbie" boat owner, so I would recommend he either Googles, or buys himself a good book on the correct method of installation for Thru-hull fittings.
As it would appear the manufacturer has either installed undersize fittings, or cut the hole too big, one might question if they even bothered with backing plates ?
I used 3/4" ply backing plates when I installed my Thru-hulls although I've read here on CF of people using a type of plastic or phenolic product which may be a better choice over plywood.
Perhaps the OP would care to tell us if the manufacturer did, or did not install backing plates just so we know the advice offered here is correct for a safe installation. This does not imply the OP does not know what he is doing, but neither should we 'presume' anything either.
The OP needs to know the correct way to install and tighten the flange nut against a backing plate, as well as drill and tap a hole in the flange to attach a bonding wire if not already done. Some people will clamp the bonding wire to the fitting but I feel this leads to corrosion of the bare wire at the contact point, so I prefer a machine screw and appropriate wire terminal.