79 Terry 450 Transom rebuild: plywood "toaster" vs. skin removal vs. seacast

Dabbler_E

Petty Officer 1st Class
Joined
Apr 20, 2009
Messages
338
79 Terry 450 Transom rebuild: plywood "toaster" vs. skin removal vs. seacast

Hi all,

Purchased this boat a couple years ago. Transom is soft and beginning to bow out, probably due to the 50 (yes count them 50) screw and bolt holes. The plywood (which is still mostly intact but quite soft and delaminating) is contained within a pocket about 33" wide (not sure how tall yet), rather than running across the entire transom.

Cutting out & rebuilding the pocket from the inside would be very difficult.

Cutting off the skin from the outside would be much more doable, but I'd rather not go that route if possible.

If I replace with wood, would it be possible to fabricate & seal a replacement piece and then just insert it between the intact skins like toast in a toaster, using epoxy & filler around the edges to avoid voids? Or would that not provide a good bond to the skins?

The other option without cutting the skins would be seacast, which will run about $250.

Thanks in advance for sharing your experiences & expertise!
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,174
Re: 79 Terry 450 Transom rebuild: plywood "toaster" vs. skin removal vs. seacast

Re: 79 Terry 450 Transom rebuild: plywood "toaster" vs. skin removal vs. seacast

Working from the top down I would use composite pour in, an elec chainsaw and a long paddle drill wood bit should take care of the removal .
Nida-core is half the cost of seacast and works good from reports.
http://www.nida-core.com/english/nordprod_nidabond_transom.htm


I did mine with seacast last yr, tape all the screw holes with duct tape.
My inside wall fell apart, I cut a plywood dam , glassed it well both sides and sealed the edges, inserted it to create the transom pocket, I left it in there.
 

Dabbler_E

Petty Officer 1st Class
Joined
Apr 20, 2009
Messages
338
Re: 79 Terry 450 Transom rebuild: plywood "toaster" vs. skin removal vs. seacast

Re: 79 Terry 450 Transom rebuild: plywood "toaster" vs. skin removal vs. seacast

Well, I decided to take off the outer skin. The main reasons were 1) the motor mount had broken through the outer skin and (2) a little probing showed that the inner skin is EXTREMELY think and brittle -- it would not have survived even casual contact with a chainsaw. I think the inner skin was just a thin coat from a chop gun. Anyway here's where I am:

GEDC0209.jpg

Da boat.

GEDC0210.jpg

Motor & accessories off, showing bowing & rot

GEDC0212.jpg

crack along side of splashwell

GEDC0223.jpg

Damage around motor mount bolt (splashwell side)

GEDC0262.jpg

Skin off

GEDC0264-1.jpg

Stringers appear to be solid
 

Dabbler_E

Petty Officer 1st Class
Joined
Apr 20, 2009
Messages
338
Re: 79 Terry 450 Transom rebuild: plywood "toaster" vs. skin removal vs. seacast

Re: 79 Terry 450 Transom rebuild: plywood "toaster" vs. skin removal vs. seacast

GEDC0265.jpg

Inner surface of outer skin -- not sure what created those grooves but they are deep and they make me very unhappy.

GEDC0266.jpg

Close up of grooves inside of outer skin
 
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