28 BERTRAM OUTBOARD CONVERSION

[DAYTRIP]

Hey Grinder.

The "tub is 48 inches wide on mine. I have a lot of buoyancy in the boat already given the beam so I kept it as small as possible. I am mounting Yamaha f250s and the centers are 28.5". It happens that the existing stringers are on the same center to center dimension so they do align with the mounting centers. I followed the rule of thumb that the cavitation plates will mount 1" per foot of set back higher than they would at the transom. so for 30" I will be 2.5" higher. The bracket bottom slopes up at the same angle (1"/Ft). I stepped up 2.5 inches from the bottom to get the bracket out of the water when on plane so the back of the bracket is 5" higher then the bottom of the boat. My clamping board is 2.25" of core and 1/4" glass on each side. As I calculated it for a 6 inch cantilever that was sufficient. I am thinking of building to 3" total thickness though.

[Grinder]

Thank you!
That's some solid information, very much appreciated.
Aloha

[DAYTRIP]

Got the balance of the gelcoat off the bottom last weekend and today I did a first fill coat. I have learned multiple thin coats is the best and easiest way to fill and fair. The aft 12' has a new skin of 2 12oz biax so it will take a couple fills. The forward part is just a skim to level the grinder marks. Hope one will do it

[Rickk]

Don't take this the wrong way but you have a BIG bottom

[DAYTRIP]

Classic! It is big. About 200sf

[Mbiggerstaff]

That looks familiar. Seems like a dream I had last year.

[Cracker Larry]

Seems like a dream I had last year.

Nightmare Been there, done that, ain't doing it again

[DAYTRIP]

Nightmare is right! I am done up to about the berth so in the home stretch for fill coat. I have about 30 hours, 4 gallons of epoxy, 12 yards of db1200, and 3 lbs of phenolic bubbles into it so far. Probably another 4-6 hours before I prime. If this ever gets anti fouling paint again I might cry.

[Grinder]

That's a lot of bottom for sure. Sure is sweet doing it turned over versus overhead. I remember repairing what seemed like a gazillion blisters on my dads 33 Bert......all overhead, real fun!
What's your secret mix for fairing compound or do you use a premix?
Looking good!
D

[DAYTRIP]

Hey grinder, same thousands of blisters on this one. That is why I took all the gel coat off. The blisters don't go much past the gel coat into the first layer of mat. I use the epoxy Jacques has here with 2/3 phenolic bubbles and 1/3 cabosil. I add it till it gets to a consistency that is easy to spread but not sag.