I have been restoring a 1982 204c Overnighter for the past three years. the boat was poorly maintained and was kept in the Toms River for years without ever coming out of the water. The boat is now only going to be in fresh water back in Pennsylvania for good. The boat was completely rotted but has since been restored except the transom. :bang There aren't any visible cracks on the inside or outside with only a few bolt holes.The boat finish on the transom is in very good shape. Can someone tell me if i should cut and repair the back of the boat with new marine plywood or use the pourable seacast product. Thanks alot! :hmm
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Help Please!
- Thread starter mrmud73
- Start date
The problem with using a filler like Seacast is that it is very dificult to remove the old rotten wood and / or to get to all of the rotten wood. You need to determine the extent of the rot and go from there.
richie rich
Well-Known Member
cut the skin from the inside and replace the core with marine ply and epoxy...it will last another 30 years
I don't think you can get to all the transom from the inside since there are two lockers and the motor well. You will probably have to cut the outside. If you cut carefully and cleanly, you may be able to remove the panel in one large piece and reuse it. Whether that is worth the effort, I can't say.
BobP
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Irrespective of using sheet material or pour it, the same prep applies so it bonds properly to existing glass.
If you do sheet from the outside it is much less work.
Sheet material namely marine plywood and epoxy resin done right is permanenet and the most cost effective when doing it yourself.
If you do sheet from the outside it is much less work.
Sheet material namely marine plywood and epoxy resin done right is permanenet and the most cost effective when doing it yourself.
richie rich
Well-Known Member
Problem is, the outer skin is the thickest and strongest part of the transom...cutting from the outside may be easier as you look at it, but you'll never get the same strength as original.....once you cut the skin, no more continuous layers...and when you re-skin, what do you have left to attach it to, 3 to 6 inches of perimeter?? You're supposed to overlap 3 inches per each layer of glass.....even with 1708 with matt, you're talking 5 layers minimum...that's 15 inches of overlap/laminating area if you do it by the book.....you can go around the sides, but then you've got lots of fairing to do...and reusing the outer skin you cut out...what for? It doesn't add any strength and you'll still have to sand and fair it.....I'd rather have all new wet on wet glass than glueing back the old skin. And how do you properly clamp in the new core when bedding from the outside when the inside is not fully accessible?
Going from the inside may seem like more work initially, but in the long run, you'll have a better product.
Going from the inside may seem like more work initially, but in the long run, you'll have a better product.
BobP
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If the inside is open and clear it's a no brainer easier too, but all those structures on the inside take a long time to get out and then restore back, including fairing work which is very time consuming.
If one is already there doing everything else, fine. Way easier.
If the pieces of ply or board material are all cut by layer and prefit and the first is bedded with plenty of thickened resin on the trowel plus 1.5 oz mat loaded up, pulled in via prefit screws and blocks from inside, nothing is separating that joint. The key is to prefit and cut everything beforehand incl. how to pul first layers in tight from inside then remaining layers from outside in. My transom is 2.5 inches thick, several layers would go back with joints in each layer staggered. I'd cut the outer skin futher away from edge as I've seen, more time for me but more skin to scarf (more cost to customer on pro jobs).
Then with slow hardener out of the sun and mod temps, it all goes in as one shot no stop work.
Come back later for outer skin.
I'd add more glass to inner skin first, all by working in a sitting or standing position, no knee pads, no climbing in and out of boat. When it comes time to match up outer skin scarfed back, one can 50 grit belt sand off a ply of wood easy since it is ply by ply - if new transom is too thick, or add glass if more is needed.
I would say most transoms are done from the outside other than for full restorations, the last few boats I've seen here started off as gas tank and soft floor spot jobs turned out to be replacing 90% of the wood in boat, and a full season or more to restoration.
RAYBO would be a good source for recommendations on any boat model and age, and the quote that goes along with each.
If one is already there doing everything else, fine. Way easier.
If the pieces of ply or board material are all cut by layer and prefit and the first is bedded with plenty of thickened resin on the trowel plus 1.5 oz mat loaded up, pulled in via prefit screws and blocks from inside, nothing is separating that joint. The key is to prefit and cut everything beforehand incl. how to pul first layers in tight from inside then remaining layers from outside in. My transom is 2.5 inches thick, several layers would go back with joints in each layer staggered. I'd cut the outer skin futher away from edge as I've seen, more time for me but more skin to scarf (more cost to customer on pro jobs).
Then with slow hardener out of the sun and mod temps, it all goes in as one shot no stop work.
Come back later for outer skin.
I'd add more glass to inner skin first, all by working in a sitting or standing position, no knee pads, no climbing in and out of boat. When it comes time to match up outer skin scarfed back, one can 50 grit belt sand off a ply of wood easy since it is ply by ply - if new transom is too thick, or add glass if more is needed.
I would say most transoms are done from the outside other than for full restorations, the last few boats I've seen here started off as gas tank and soft floor spot jobs turned out to be replacing 90% of the wood in boat, and a full season or more to restoration.
RAYBO would be a good source for recommendations on any boat model and age, and the quote that goes along with each.
BobP
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How are you figuring 15 inch?
12:1?
Lucky one can find 1/4 inch back there, down lower to bottom it gets thicker. And perhaps hull sides to rear at the turn.
Shows glass scarfs with and w/o sandwich or primary backup. The new wood behind scarf is bonded and considered, not the same as rest of a hull span of non-cored straight hull out there by itself alone.
Basic stuff off internet. Good sketches. Shows two styles of bridging the gap as well.
http://www.ericgreeneassociates.com/ima ... Damage.pdf
1/4 inch would be 3+3=6 inch wide @ 12:1.
Doubt more than 3/8 in. exist back there, for a 9 inch wide gap.
12:1?
Lucky one can find 1/4 inch back there, down lower to bottom it gets thicker. And perhaps hull sides to rear at the turn.
Shows glass scarfs with and w/o sandwich or primary backup. The new wood behind scarf is bonded and considered, not the same as rest of a hull span of non-cored straight hull out there by itself alone.
Basic stuff off internet. Good sketches. Shows two styles of bridging the gap as well.
http://www.ericgreeneassociates.com/ima ... Damage.pdf
1/4 inch would be 3+3=6 inch wide @ 12:1.
Doubt more than 3/8 in. exist back there, for a 9 inch wide gap.
richie rich
Well-Known Member
Bob, I was referring to wet on wet new glass layup vs scarfing for a hole repair, say for the side of the hull. When glassing new laminate, each successive layer of glass should overlap the previous layer of glass by at least 3 inches....that's industry standard for new glass layup.......when the boat is made in the mold, the layers at every edge normally overlap by 3 to 6 inches...this is what makes the glass a "continuous layer" and unifies the structure....so if your laying up a new transom from the inside, the first layer goes beyond the core and around the corner by 3 inches onto the gunwale....the next layer will be 6 inches on the gunwale, the next layer 9 inches..until you complete all 5 layers......that is how the original inside skin was laminated at the factory, hence you will notice the thicker gunwale area at about the 1 foot mark of the transom/gunwale corner of a boat.
If you try that method from outside, you run out of real estate unless you decide to wrap around the corner and around the hull bottom.....a 12:1 scarf joint repair on a transom??? It may look nice once the paint or gelcoat goes on, but in no way is it as strong as the other original method. The transom holds the boat together and the motor is trying to rip it off....at 12:1 on a 1/4 or 3/8 inch outside skin, 3 to 5 inches of resin/glass contact to the original vs 12 to 15 inches is no match. Plus I don't see how you can properly clean the inside of the remaining lip of outer and inner skin with only a 2 to 2.5 inch space...my Makita grinder will never reach anything past 2 inches in...so the bond to any unprepped area in the corners will be nill. How do you get all that stuff out and grind to clean glass??
I know what you're saying about people doing it all the time, but I personnaly don't like doing it that way unless its wrapped around the corners of the boat and faired. Just my .02 cents
If you try that method from outside, you run out of real estate unless you decide to wrap around the corner and around the hull bottom.....a 12:1 scarf joint repair on a transom??? It may look nice once the paint or gelcoat goes on, but in no way is it as strong as the other original method. The transom holds the boat together and the motor is trying to rip it off....at 12:1 on a 1/4 or 3/8 inch outside skin, 3 to 5 inches of resin/glass contact to the original vs 12 to 15 inches is no match. Plus I don't see how you can properly clean the inside of the remaining lip of outer and inner skin with only a 2 to 2.5 inch space...my Makita grinder will never reach anything past 2 inches in...so the bond to any unprepped area in the corners will be nill. How do you get all that stuff out and grind to clean glass??
I know what you're saying about people doing it all the time, but I personnaly don't like doing it that way unless its wrapped around the corners of the boat and faired. Just my .02 cents
gw204
Well-Known Member
Cut the inside. That way you can pull out the entire aft section of the cap and get a look at the stringers...or what is left of them.
thanks for the info fellas but i should have given you more to go on . got the GW three years ago from a buddy at the NJ shore. He gave it to me, all it cost was a trailer to haul it. He also gave me a wet carpet a rotted floor and a lot of other rot from bow to transom all of which done in new glass and marine ply never thought it went up the transom like a sponge until i went to change a simple scupper flap... surprise more rot! Lucky I'm a project guy do most everything myself oh, and i cant forget the 10 or12 coats of anti fowl paint that i soda blasted off. Brand new white bottom looks great always wanted a great Erie boat just one more repair away the 200 merc black max is newer and runs great. Thanks again and i'll let you know what happens and try to get some pics posted.