MacGregorSailors.com

We're excited to have been gifted a 78 Mac 25 which seems to be in good condition. Much of the boat appears to be in original condition with minimal modifications. We are planning to leave it moored for some longer periods so wanting to add an automatic bilge. The current manual bilge is drawing from what appears to be a boxed in area next to the battery. The lid to this area is secured with a huge number of screws and also seems to be sealed/corroded shut. (attaching an image)

We are wondering what the purpose of this fortified box area is, and if it is important for us to open this area in order to position a new float switch? Or can we just leave this alone and put the switch elsewhere?


Thanks for any help!

I can't quite tell, is that the area where you sit at the dinette table? If so, my 25 just had free floating plywood covers over that hole and the battery was down inside it. No idea why he would have sealed it so securely. all of the bilge areas are connected though, except that the centerboard trunks closes them off all along the centerline of the cabin. To make it work, you would need to install a pump pretty much anywhere on both sides of the centerboard trunk. However, unless someone has installed a lot of underwater thru-hulls, there is no opening in the 25 that could cause you trouble. Even the bolt for the swing keel is above the waterline. You can seal up any rain leaks and not worry about it.

Hi Jcromett

First, CONGRATULATIONS on your new Mac!

Wow! Someone wanted to seal up something!!!
I can’t immediately recall any Mac ever having that kind of a feature….
If one were to guess one might assume that the modifier wanted to make an under lip flange for a rested lid but that would only explain the outer perimeter of screws …. Not the inner perimeter set of screws…. Nor the extra two in the more central area….???

The corrosion you mentioned might possibly be old adhesive like 5200.
If so then maybe someone wanted to make that compartment water tight??? Why???

A built in fresh water tank maybe?
But there would have to be a fill port and a drain line somewhere….

An extra water ballast compartment to increase sailing stability?
But that area is higher than the normal ballast fill vent would be….

Looks like you are well on your way to a mystery!

If you haven’t already done so, soaking the screws with a light penetrating like WD40 might help with corrosion.
If it is old adhesive a little bit of warming with a heat gun should soften it some.
Maybe a combo of both penetrating oil after heating?

Good luck!

Congrats on the boat. At that price you can't complain about anything.

That looks like some serious work to shut that compartment up. It would make me most curious what's under there. Al Capone's vault?

If that is the dinette seat, it could be valuable storage space. If it were me, I'd find a way to open it.

Was Hoffa ever found?……….

I must admit I as curious as Russ is for you to expose the mystery of the sealed bench …..

Yes, someone went to a lot of effort set up and installing 30 screws to seal off a storage compartment…?

Thanks for the replies and interest. We're holding off on busting it open for now so we can focus on getting her on the water!