captrod28

I am getting conflicting procedures for re-glassing my transom. I have a magnum 25 that I just removed a volvo 280 drive and want to install a mercruiser bravo 3 drive. The volvo transom cutout is much larger and needs to be closed up. I also have two through the transom exhaust holes that need to be closed up as well. The transom seems dry and soild. Can anyone help me out. Thanks.

dereknkathy

there is an adapter plate bolts to volvo cut-out with a merc cut-out in it. pricey at 8-900 bucks. the problem with filling the hole is the transom mount is where ALL of your 260 to 700 HP pushes on the boat. pushes in on the bottom of transom and pulls out on the top. i might trust a transom glassdave filled. i wouldn't trust one i did.

Cobra100+

iTrader: (3)

Get a good glass guy to do the work and it should be fine. People glass them up all the time for damage repair, change of drive type, increase the "X" dim etc...

vintage chromoly

iTrader: (3)

i did my 24 foot pantera. i had a volvo 280 and two exhaust cutouts to fill.

i bought the adapter plate like the above poster is recommending and i promply sold it. it was MASSIVE!
also, you have to enlarge the volvo cutout to accept the adapter.

i decided to glass mine in and i'm glad i did for a couple of reasons. one, i can set the "x" dimension at whatever i want now. two, it would have looked like crap with that giant adapter as well as the plate weighingclose to 50 pounds. third, it's the "right" way to do it.

i cout out the outermost 3/4 plywood and glass to a larger size than the volvo hole by 4 inches aorund the perimeter and cut a panel to fill the void. then i made a filler for the volvo cutout to be glassed in from the bilge side. lots of layers of cloth and epoxy later i had a faired out and flat transom that is "virgin" for the new rigging.

here's a couple pics:

vintage chromoly

iTrader: (3)

a few more:

vintage chromoly

iTrader: (3)

primered and ready for finish blocking:

dereknkathy

i wasn't recommending it, i was mentioning it's existance as an option. i was recommending replacing the transom.

glassdave

iTrader: (1)

nice example pics VC, thats the way to go if you have a good solid transom to start with. I usually step it like that on both sides carefully with a router to a depth to accommodate a half inch ply on both sides then cut another piece of half to exact dimension of the existing Volvo hole. Three pieces of wood in the laminate to make up the thickness and sort of encapsulated sandwich affect.


This was a high strength transom i helped C Spray with on his conversion from Volvo to big Illmor. Chuck took a lot of care to plunge cut the steps and we dressed up every stage of the process for maximum strength. The middle inner most piece was bonded in first and allowed to cure then dressed up on both sides to give a perfectly uniform landing for the two outer pieces.


This can be done without bagging, we chose to tighten up this one as much as possible and gain the benefit of getting the fiber close together.

glassdave

iTrader: (1)

because it was going to hold a much larger drive and plenty more HP we did a couple kick ups on the inside to help handle the load. Remember the bottom will be under compression and the top under tension.

Also a cross section of the cutout

captrod28

thanks! this is what I needed. what type of cloths do you recommend?