1978 with a serious Porpoising problem

[Cloaked]

Originally Posted by Theomedic

How about a trim tab? I'm willing to try it.

That is the one thing I did not test. You're own your own there.

The reality is this (from my point of view and experience): Anything you do will only disguise the consequences of the problem. The root cause will not go away.

Sorry that you are experienceing this issue.

Short of a long story for me... I talked to a lot of people about my 79 (back in 79 - 80) and I ran into a guy here that used to work glass at Mastercraft. His bottom line was that the mold that the hull came from created this problem. Not much one can do about it, I was told.

Hopefully you can find a resolution from further research and discovery, but I conceded the 79 to another buyer, said buyer fully knowing the issue. He said I'll take the boat and I can fix it... I was on that (nearby) lake for another while and he never did fix it, doing all the things you and I have both tried (less the trim tab). Maybe a genius from Texas, or someone with knowledge of a fix beyond my efforts, can suggest something to to resolve.

.

[ahhudgins]

Originally Posted by Theomedic

How about a trim tab? I'm willing to try it.

You mentioned that your temporary hook came off so I’m guessing that you really didn’t get much of a test? Adding a trim tab does the same thing as a hook, so you might want to give the hook another chance before spending the time and money on the tab. My Maristar 200 used to ride bow high and only porpoised when I had more than 3 people in the boat, and it got worse when I added more weight (even the bow).

My hook is a piece of nylon that I cut like a wedge and it’s only 3/16 inch at the trailing edge. I used “Goop” to glue it to the hull. I put Goop on the strip and held it in place with painter’s tape and shoved some wooden dowel between the driveway and the strip to keep pressure on it. I let the Goop set up for at least 24 hours and then smeared the Goop over the leading edge of the strip. ¼ wedge was too much and took 2 MPH off my top end. I filed it down to 3/16 and it worked perfectly. The boat planes quicker and I lost no top end speed. One winter I will have mine fixed if I can find a gel coat guy who knows what he is doing.

I had 9 people in my boat this weekend, no porpoising and I could still hit 41 MPH with a few “Big Girls” in the boat. You may have a bigger problem with your hull or stringers, but my neighbor added the hook to his older S&S and it fixed his problem.

[Theomedic]

I'll give it a try, can you give me some more info?
Where can I get the nylon?
How wide is the nylon 2-3 inches?
How did you cut the taper?

[madcityskier]

There's a boat that just showed up on facebook on the mastercraft project page that had this home repair for porpoising. Thought you would like it. He's planning to remove all this during the restoration and go with something more subtle like what ahhudgins did.