Marine heads, fiberglass and jig saws - H30

[malyea]

UPS delivered my new Raritan PHC LBA (to replace the original Mansfield head) and I need to do a little cutting and drilling to make it fit.

I've never cut or drilled fiberglass before........

I need to cutout/elongate the bulkhead hole by about 2 - 3" where the waste hose routes forward off the 90 deg elbow to the holding tank. Use a fine bladed sabre saw and masking tape to protect the edges....what else do I need to consider?

I also need to drill 4 new holes for the base mounting bolts to properly position the head for installation. The original bolts are course threaded lag bolts that seem to be threaded into a backing of maybe plywood molded under the fiberglass base that the head sits on.... There's zero access to the space below the head to visually verify what's there - does anyone know what I'll find when I drill the new holes? Tips, cautions, etc for drilling fiberglass?

Thanks

 

[Ed Schenck]

I use a Roto-Zip for cutting holes or enlarging existing one. Much easier to get a clean cut, especially in tight quarters. You are correct, there should be a plywood coring at the base of the head. Drill one small, maybe 1/4", hole to verify. Other than to be sure that I had a sharp bit I never had any issues.

 

[Steve Dion]

Before you start cutting, check with Raritan to see if they have any additional fittings that may eliminate having to cut more/larger holes.

Yes, the toilets are normally held down with lag bolts. I usually try to use any of the existing holes when replacing the toilet, but that may not work in every case. Also do not be afraid to extend some hose to make everything fit better without alterations.

 

[Peggie Hall HeadMistress]

I'm not sure why...

...you'd need to enlarge any holes in bulkheads that hoses pass through. Are you sure that a new straight or 90 (depending on what you have now) discharge fitting isn't the solution? If the right one didn't come with the new toilet, Raritan will replace it.

But it is highly likely that you will have drill at least two more holes to mount the PHC base (and fill those you won't use), 'cus even the newest model of the same make/model isn't likely to match the old holes. And yes, they are lag bolts, so you don't have to worry about what may or may not be under the head sole.

You prob'ly will need a new longer intake hose too...'cuz, unlike most toilets, the inlet fitting on the PHII/PHC is on the front the pump, which means you'll need an intake line that's about 6" longer.

But once you have it installed and working, you will understand why so many people really do like this toilet...and you will too!

 

[Mathurin]

I second Ed Schenck, use a Roto-Zip or something similar instead of a Jig saw. If you think about doing some other mods that recquire cutting fiberglass in the future, you may also consider buying a dedicated fiberglass router milling cutter such as theses:
http://img.directindustry.com/image...-cutter-for-fiberglass-applications-62282.jpg
I guess some hardware store probably have them but I found mine at Napa auto parts.

 

[Steve Dion]

Those Roto-zip tools are very cool, but be careful. When you start cutting into something like plywood, they can get away from you and you will have a bigger/mis-placed hole than you planned on.

 

[Mathurin]

As for drilling, you can use a normal drill bit for wood of steel (whathever you have in your tool box). I would not be too worried about the depth, but if you want to make sure you don't go too far in, just put some tape around the drill bit to do a stopper, take the length of the screws you removed as a guide.