26M Fibreglass Thickness

[45Plus+]

Hello All

After poking around various threads, I've yet to find information on the thickness of a 26M hull, deck, cabin, liner etc. I am in the process of remounting the fuel filter/water separator that the PO had simply screwed to the wall of the motor well. I think Well Nuts are the way to go as 1) its pretty much a blind mounting as you can't easily access the inside of motor well wall, 2) the need for a watertight seal and 3) to deal with any vibrations given proximity to the motor. So, the big question is, how long do the well nuts have to be to accommodate the thickness of the fibreglass in this location? It is something I'd like to get right first time around as I imagine removing a mis-sized well nut (especially too long) would be difficult at best.

This small task got me thinking about the thicknesses of the fibreglass throughout the boat and wondered if anyone ever compiled and published a survey of thicknesses?

Duncan

[LordElsinore]

I mounted a fuel water separator in my motor well with rivet nuts. From memory the fiberglass is only about 1/4 inch thick at most there

[45Plus+]

Thanks for the speedy reply! I do have a set of rivnuts and driver that I could try - though not stainless steel. As I will likely have to order or drive around to find them, I may just go with the well nut approach for the reasons I listed.

You'd think the thickness of fibreglass could be found in a technical specification for each Mac boat type. Someone, somewhere must have the original recipes .

[Russ]

Hmm....I simply screwed my filter/water separator into the side of the motor well as your PO did. Was before I knew of rivnuts.

I have drilled through a large access hole to get to the seat hinge bolts. It's not thick. Maybe 1/4"

As for specs, you won't find any. Especially wall thicknesses. I think you will find most of the deck is the same thickness.

[45Plus+]

Thanks Russ. I will give the PO his due in that the screws held up well and only have begun to loosen in their holes. My (unfortunate) choice of fuel filter/water separator also means I have to subject the filter mount to a good deal of torque to spin off the filter cup (lordy knows who would have ever engineered such a thing...). I am hoping a well nut or rivnut will be able to resist working the drilled holes and loosening up the mount. Time will tell.

At least I have a couple of weeks to launch given high water is keeping our club's docks out of the water. I've got a long list of things to do....

[Russ]

I wish I had known of rivnuts before I mounted my filter with screws. They seem like a great solution for many fiberglass attachments.

YES, those Raycor filters come from the factory with the filter torqued on so tight. Fortunately, I read about this BEFORE mounting the thing on the boat. I removed the filter on the bench with the help of some muscle and tools. NO WAY could I have gotten it off with the housing mounted on the boat and it certainly would rip my screws out with the force it takes.

What I did was remove the filter before mounting, lubed the gasket a bit with some oil, and reattached with LESS torque. I haven't replaced the filter yet but I'm hoping when I do it will come off easier.

[45Plus+]

I read about the difficulties people have had unscrewing the cups on the raycor filters and also pried it open in the vice in my shop (with a long armed filter wrench). When I put it on the boat, I found it had to be tightened up quite a bit to prevent it from leaking (still have the open topped coke can tie-wrapped beneath it just in case). We will see this season how it does....once I replace the screws.