Mac'M Ballast Tank Leak ?

[phil kelly]

There's a brand new Mac M on my marina today, been there for a week seemingly unlaunched I thought, however, it transpired the boat had been launched during the week but began leaking internally when the ballast tank was filled. it was pulled off the water,tank emptied and put back in overnight without filling the tank, the result, no leak.
Further filling of the ballast again resulted in an internal leak, fine weather no rain.

First conclusions are that the ballast tank has a leak although there are no obvious signs apart from the boat beginning to fill up. I have never heard of this defect on a macgregor as I should hope they pressure test the tanks during construction.
Has anyone heard of this problem before or any suggestions as to any other possible causes. This Mac' has been supplied by the UK agents, the poor owner waited months for delivery from the US and will not be looking forward to a long wait for a replacement I'm sure.
Phil Kelly UK

[Catigale]

hope they pressure test the tanks during construction.

Really? I doubt they do this. Shouldn't be hard to confirm this, but fixing it could be a Charlie Foxtrot

[Mac26Mpaul]

Seems very strange. The glass that makes up the ballast tank is pretty dam rock solid (not exaclty paper thin thats for sure) as is the hull, at least under the water line. I dont see how it could have a leak (???) Can't they find where water is coming in when its in the water or try filling the tank when its on the trailer?

Theres going to be a flurry of excitement on the anarchy forum when this one gets out

[Ixneigh]

Yea I'm no engineer but if I was making a Water ballasted boat no amount of abuse would rupture the tank. It would be integral to the hull. First place I would look is the fittings and valves and plumbing. Might turn out to be a simple fix.

Ixniegh

[pokerrick1]

If I were the owner I would make an overseas call to Mike Inmon at the factory and see if he could enlighten me - - - I betcha he could

Rick

[dennisneal]

The ballast tank normally has two holes: the ballast gate in the rear, and the vent hole in the bow. If the vent hole is not sealed by a stopper the water inside the ballast tank will leak into the interior of the boat when the bow moves up and down due to wave action or the boat's motion.

I know this is a "dumb" reply to the person's problem, but I'd check to make sure the vent hole has been tightly sealed. The fiberglass covering the ballast tank is really quite thick and is composed of several layers.

[Wa2paa]

Try the Detective solution of , Taking a small vacuum cleaner output side. Press fit the Output hose into the Ballast Tank Vent. Turn on the Vacuum Cleaner , with the Ballast Gate valve closed, and You will find the leak... Air rushing out of a small hole "Maybe from a SCREW that has penetrated, the ballast while attaching some add on, like 2nd Battery tray, or etc .

These type of leaks, are caused by an errant Drill Bit, that has gone too deep, while adding options.

Best of Luck

Captain Jack

[Mac26Mpaul]

Somethin fishy goin on ere I reckon. Be interested in hearing the outcome

[Divecoz]

Agreed.. and I for one dont buy a word of it ... I think .... its a troll post ....and as it's been said before Don't Feed The Trolls.......

Somethin fishy goin on ere I reckon. Be interested in hearing the outcome

[yukonbob]

I would also throw some food colouring in the tank and make sure it is the ballast. I would also second the 'aftermarket penetration' and not a factory issue.

[pokerrick1]

Better make it a beighish color dye - - - red could get real messy inside

Rick

[Newell]

Could be a factory defect, I know the early water-ballasted D models had problems with ballast leaking internally. I know this because I own one. Leaks underneath cabin sole.

[Catigale]

I recall pictures on this site of a bad layup area on top of the tank that oozed water. Cant imagine trying to fix that under the liner or floor...

[Russ]

Ballast leaks are EXTREMELY rare I'm told. The obvious things like vent plug have been checked I hope.

Please let us know the results. Like I said, I've heard these leaks just don't happen. This may be the exception.



--Russ

[phil kelly]

Went down to the marina today,the Mac M sat on it;s trailer with 2 inches of water on the cabin floor, on investigation found the batteries in the usual place ( I think ) under a cover below the steps down---yes you've guessed it--- batteries screwed into the ballast tank ! not only that they had been screwed down in one position first and then relocated a few inches over leaving two further holes through the ballast tank casing unfilled,
This was confirmed further by sealing an airline into the inlet valve and applying some pressure whilst watching the air bubbles merrily splurting out from under the batteries.
I think really this is the best news the owner could hope for, the culprits are the people who fitted the engine and batteries and the responsibility for the repair obviously rests with them, I don't know who they are but I'll find out and make sure I never use them ! (Sorry Mr. Macgregor for insinuating that your ballast tanks could leak)
Phil Kelly UK.