1978 Proline 20 Rebuild
#121
#123
Admirals Club 

Thread Starter

More progress has been made. Putting a layer of 1708 on the entire inside of the hull and hull sides. Glued in the transom board. Waiting for my shipment of resin and shopped fibers to finish the transom. Need some thoughts and ideas for the cap where it used to meet the transom. It is not fitting back on which may just be an adjustment issue. But I want to hear some thoughts on how to finish it.




#124
Senior Member

I had a similar issue with mine after removing it but not as much. Mine was about 1/4" off where yours looks about 3/4" to short.
If you remove it, flip it over and grind the inside edge of the flange smooth so there is nothing sticking out it will help. Any fiberglass you put in covering your new core pieces that added thickness to the flange will also make the inside of the cap smaller than it used to be.
One more thing that will help is to use a grinder on the hull and bevel the edge all the way around at about a 45 degree angle. It kind of helps the cap to slide past the hull rather than just catching on it and not going down any more.
If you remove it, flip it over and grind the inside edge of the flange smooth so there is nothing sticking out it will help. Any fiberglass you put in covering your new core pieces that added thickness to the flange will also make the inside of the cap smaller than it used to be.
One more thing that will help is to use a grinder on the hull and bevel the edge all the way around at about a 45 degree angle. It kind of helps the cap to slide past the hull rather than just catching on it and not going down any more.
#125
Admirals Club 


On my Mako the original transom core didn’t go all the wall to the side. It looks like you cap might be hanging up on the core.
#127
Admirals Club 

Thread Starter

Go most of the gap between transom board an hull sides filled with thickened epoxy. Used cabosil and milled fibers. Baby woke up from his nap so I will have to finish the rest next week when Im off. Plan on glassing the inside of the transom with 3 layers of 1708. Should be rock solid. Almost 2 inches thick


#128

I despise them as this “ hatch” is the main reason tanks get trashed. Being a mako guy, I rebuild deck with zero hatches or any protrusions that WILL even rly let water in.
#131
Admirals Club 

Thread Starter

More progress and a little hiccup. Glassed in the transom and as it was curing the gator board blew some bubble. I plan on adding another layer so ill grind out the air pockets and move on


#132
Admirals Club 


Hate that. Had a similar issue with my fish box using CSM and VE resin. Still don't know what caused it but like you, just ground them out and moved on.

Looks great otherwise!

Looks great otherwise!
#135
Admirals Club 

Thread Starter

Slow progress but progress. Ground down all the little air voids and filled them yesterday. Glued in the first knee support to the transom.


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#139
Admirals Club 


Sub'd. Awesome build. Didn't know this particular forum existed until a week ago.
So best I can tell is you filled the cutout with 2 layers of 1708 (added 1 more 1208 later), then added 3 full layers of 1708 tabbed into the hull, added 1.5" core, then glassed in 3 layers of 1708 on the inside? Do you remember what the thickness of your existing fiberglass shell was at the transom?
Are there ways to prevent the core from bubbling? Maybe wetting it out first, then waiting until tacky before adding glass? Would like to avoid that issue if it's possible.... I'm almost to the point of installing my core.
So best I can tell is you filled the cutout with 2 layers of 1708 (added 1 more 1208 later), then added 3 full layers of 1708 tabbed into the hull, added 1.5" core, then glassed in 3 layers of 1708 on the inside? Do you remember what the thickness of your existing fiberglass shell was at the transom?
Are there ways to prevent the core from bubbling? Maybe wetting it out first, then waiting until tacky before adding glass? Would like to avoid that issue if it's possible.... I'm almost to the point of installing my core.
#140
Admirals Club 

Thread Starter

Yes that was the schedule for the new transom. The original thickness was around 1.5 inches. The new transom is just over 2 inches thick. So yes I have figured out how to avoid the bubbles when i started glassing in the second knee. Basically coat with a thin layer of resin and let the heat off gass the would be bubbles. Then laminate.