KC_Sundancer
Active Member
- Sep 8, 2009
- 1,341
- Boat Info
- 1985 270DA Sundancer,Simrad 4G Radar,Lowrance Gen2 GPS/Sonar/Structure Scan,F350 7.3l Diesel, tri-ax
- Engines
- twin Mercruiser 185R's (v6's) w/SE106 drives, "High Five" stainless props, Mercury 280 RIB w/9.9 Mer
Transom Rot - a bad thing but repairable with time and some basic tools.
This was my biggest restoration project - tasked by not having a big enough building to put her in and an average winter snowfall over 180 inches.
With much research and many different viewpoints, I tried to incorporate the best points of all of them and add a few of my own.
Below I go through the repair steps, with many photographs, for those who may want to tackle a similiar project.
(If pics do not show refresh the webpage)
Transom Replacement
When the boat was purchased there were tell-tail signs of a rotted transom. With this in mind and knowing I could do the work myself (as a design engineer - not a fiberglass guy) I made the purchase with a drastically reduced price. In the end the transom work cost me around $1,500 in material and about 3 months of work, a few days a week.
Two issues caused this rotting problem.
First was when the boat sat in the water there was a slow leak from a hole from the original swim platform that was improperly filled. This overtime caused serious wood rot in the transom. The fiberglass on the inside of the transom could be pushed in easlily with a screwdriver.
The second was a common problem these "Express Cruisers" are known for having. The large sliding cabin windows do not offer great structural support for the deck. Jumping, walking, etc. on the deck causes the old sealant to eventually break loose and start leaking. With steady rains it was clear that water was leaking through both windows and making it's way into the understructure of the boat. Wet carpet in the cabin, side pockets and sometimes under the cushions in the mid cabin are signs of the windows leaking. An issue with no weep holes for water to drain from the foam filled compartments inside the hull assisted with more rotting. This was clear with the areas under the water heater and batteries.
The sources of the rot were fixed first. Both side cabin windows were removed, completely disassembled, seals replaced, windows rebedded and then reinstalled using 3M 5200 to bond and seal them.
Here are a few pics of the rotting warning signs:
Fiberglass delaminating from the understructure and cracking - a clear sign.
Here are a few pics of what was uncovered:
The "tea stain" hole in transom opened up - wood was like oatmeal.
Side floor under batteries and water heater - same problem on both sides.
The Beginning - clearing out the engine room:
Choosing to work this next to my house required me to be a bit creative.
I built a large "swingset" type frame out of 4x4's and 2x8's to pull the engines. This frame was then turned and extended to cover the full length of the boat to keep off the abundance of snow we get over the winter.
Frame & chain-fall ready to pull engines.
Pulling the second engine.
Once the engine was hoisted, up the boat was pulled forward on the trailer.
The engine was then lower and towed into the garage.
Second engine ready to haul to the garage.
Both engines and one drive completely removed.
Daughter Kirsten helping with pulling the fuel tank.
I did have to cut an angle on the stringers just ahead of the motor mounts to remove the fuel tank.
The shape Sea Ray built into it fell 2 inches short of allowing the tank to be removed.
The cuts allowed the tank to roll back and be hoisted out.
Here you can see the angled cuts made to the stringer for fuel tank removal - pic taken after the project was completed.
My other helper - Cedar
Engines in the garage - good time to do some basic inspection/repair.
Now emptied out, the frame was turned, extended and used to cover the boat for the winter work.
My early winter working conditions.
Now the messy work begins:
Digging out and removing the old rotted transom was a messy project.
Most important item needed is a good respirator - you do NOT want to be breathing the heavy amounts of wood and fiberglass dust.
What's needed: Respirator, Fans to remove the dust, Circular saw, 4 or 5 inch grinder, Sanding wheeels, Chisels, Hammer.
Here is my cleaning process with pics following:
First I marked where I wanted to cut the inside transom skin with a straight edge.
Then set the circular saw about 1/8 of an inch shallower than the total thickness of the inner skin and wood core.
On the inside of the boat I cut the periphery of the area to be replaced with the circular saw and removed the inner fiberglass skin.
Any rotted wood was then dug out using chisels, screwdrivers, whatever I could reach with.
The remaining "good" wood was then ground out using the 4 inch grinder. I tried everything and found "sanding" wheels worked best.
Save the clean sanding dust to use as a "filler" later on.
A thorough cleaning was done to ensure the outer hull was fully cleaned of the original transom wood on the inside.
The rotted structure on either side of the boat was also cut-out and cleaned using the 4" grinder.
First circular saw cuts to remove center section of inner transom skin exposing extent of rotted wood.
Additional cuts were made to remove the entire transom core.
Thoroughly cleaned / removed transom and side structure.
This is the best wheel I found to use in the grinder for both removal and cleanup of the existing wood and inner side of the outer hull.
Time for the new stuff:
What's needed ?
I found out the general rule of thumb for "wetting" area of fiberglass cloth by one (1) Gallon of Epoxy / Resin is as follows:
Bi-Lateral Cloth. Consists of a fiberglass matte sewn to a fiberglass cloth.
Two layers of this were used to cover the transom blending out onto the floor.
Epoxy Used:
E-cast CCA EPOXY RESIN w/ #305 HARDENER
(5) gallons total
From Eastpoint Fiberglass Sales near Detroit Mi
Aluminum Lay-down Rollers
They work great for working out air bubbles and setting the cloth laminates.
I chose aluminum so they could be easily cleaned (before the epoxy sets) for future projects.
Bolt and Weep Hole Liner Material.
Antenna Sample Pack - assortment of 6 inch long fiberglass sleeves
From: Max-Gain Systems, Inc., 221 Greencrest Ct., Marietta, GA 30068
Trim Head Deck Screws - Stainless Steel
Installing the new stuff:
Step One was to cut the pieces of marine plywood to shape for the transom and side structure.
The transom required (2) pieces of 3/4 inch marine grade plywood laminated together for the 1 1/2 inch thickness needed.
When laminating I wet the one piece of plywood with epoxy, worked in (1) layer of 10 oz. plain weave cloth, wet the opposing piece of plywood and sandwiched them together. I then used a numerous amount of 1 1/4" long stainless steel "trim head" screws to pull and hold them tightly together. The screw locations were roughly planned as they were NOT removed.
Laminated Cross Section (cut-out from outdrive holes)
The Transom section needed multiple pieces to allow installation behind the stringers. In the photo below you can see how the the laminated transom pieces would overlap once installed.
All edges of the lamination were sealed with multiple coats of epoxy before installation.
Overlap Detail
Step 2 was to install the laminated transom piece.
The laminated transom piece was test fit.
(4) holes were drilled from outside the boat for the threaded rod, one near the top and bottom of both outdrive openings.
The (4) 2 x 4's were then match drilled (through the narrow side) to these holes.
Everything was removed and the inner hull was coated with epoxy and layered with (1) layer of 10 oz. plain weave cloth.
The mating side of the transom piece was then wet with epoxy, installed and clamped to the transom using the threaded rod and 2 x 4's.
Clamped Transom Pieces
Step 3 was installation of hole liners and filling of any "gaps".
Fastener and drain holes were opened up to match the chosen tubing size, being careful to NOT go thru the outer hull.
Fiberglass tubing was then cut to length and epoxied in place.
Gaps between the transom pieces and the hull were then filled with a thick fiberglass dust / epoxy mixture.
Holes cut for the trim tab supply line and fasteners.
Trim tab holes with un-cut fiberglass tubing samples.
"Lined" drain plug hole.
"Gaps" filled with fiberglass dust / epoxy mixture.
Step 4 was installation of the side structure and covering the transom pieces.
(2) layers of the Bi-lateral weave glass were used on the inside transom with one layer of the same glass on the side structure.
The first layer was overlapped onto the "floor" by about 8 inches.
The second layer and side structure glass ovelapped about 6 inches onto the floor.
Note: "WEEP" holes were added to the aft-most corners of the side structure and exsting stringers to allow water to drain. Fiberglass tubing lined these holes as explained earlier.
The Aluminum Lay-Down roller was a big help in working out air bubbles with this final glassing step.
I did have minimal air bubbles in the side structure areas but was extremely pleased with the transom area.
Transom glass work
Side structure glass work
It was too late once I started but rounding all the edges and corners would have helped.
Working out the air would have been much easier as the glass does not like to "fold" over corners.
Step 5 Put in the Outdrive Cut-outs and Fastener Holes.
All of this was done from the outside using the existing holes and cut-out in the outer hull as a template.
I first used a 2 inch hole saw to drill two holes at the top of each outdrive opening. The holes were drilled at a 45 degree angle - see pic below. This is for clearance of the steering arm on the inside when turning.
Then the big hole was cut using a jig saw following the existing cut-out contour.
Next I drilled the outdrive fastener holes perpindicular to the transom.
They do have a drill jig available for the outdrive holes and cut-out but I opted to save a chunk of cash and just use the hull as a template - it worked fine.
These holes were too close to the cut-out to allow use of the fiberglass tubing for a liner so I used a pipe cleaner type brush to apply multiple coats of epoxy to the inside of the holes. The Cut-out also recieved multiple coats of epoxy to seal-er up.
The final step was to mix the grey pigment with epoxy and apply a final coat to everything for a nice clean colored look.
The "angled" holes can be seen here looking from the inside.
Step 6 Put everything back together !
Be sure to replace the outdrive transom assembly Seals!
A nice clean difference.
No more hanging wires.
This was the biggest of my projects, am very pleased with the outcome and glad I tackled it.
Best of luck with your repair !
For more on this boats restoration see my full story thread: http://clubsearay.com/forum/showthread.php?t=23289
This was my biggest restoration project - tasked by not having a big enough building to put her in and an average winter snowfall over 180 inches.
With much research and many different viewpoints, I tried to incorporate the best points of all of them and add a few of my own.
Below I go through the repair steps, with many photographs, for those who may want to tackle a similiar project.
(If pics do not show refresh the webpage)
Transom Replacement
When the boat was purchased there were tell-tail signs of a rotted transom. With this in mind and knowing I could do the work myself (as a design engineer - not a fiberglass guy) I made the purchase with a drastically reduced price. In the end the transom work cost me around $1,500 in material and about 3 months of work, a few days a week.
Two issues caused this rotting problem.
First was when the boat sat in the water there was a slow leak from a hole from the original swim platform that was improperly filled. This overtime caused serious wood rot in the transom. The fiberglass on the inside of the transom could be pushed in easlily with a screwdriver.
The second was a common problem these "Express Cruisers" are known for having. The large sliding cabin windows do not offer great structural support for the deck. Jumping, walking, etc. on the deck causes the old sealant to eventually break loose and start leaking. With steady rains it was clear that water was leaking through both windows and making it's way into the understructure of the boat. Wet carpet in the cabin, side pockets and sometimes under the cushions in the mid cabin are signs of the windows leaking. An issue with no weep holes for water to drain from the foam filled compartments inside the hull assisted with more rotting. This was clear with the areas under the water heater and batteries.
The sources of the rot were fixed first. Both side cabin windows were removed, completely disassembled, seals replaced, windows rebedded and then reinstalled using 3M 5200 to bond and seal them.
Here are a few pics of the rotting warning signs:
Fiberglass delaminating from the understructure and cracking - a clear sign.
Here are a few pics of what was uncovered:
The "tea stain" hole in transom opened up - wood was like oatmeal.
Side floor under batteries and water heater - same problem on both sides.
The Beginning - clearing out the engine room:
Choosing to work this next to my house required me to be a bit creative.
I built a large "swingset" type frame out of 4x4's and 2x8's to pull the engines. This frame was then turned and extended to cover the full length of the boat to keep off the abundance of snow we get over the winter.
Frame & chain-fall ready to pull engines.
Pulling the second engine.
Once the engine was hoisted, up the boat was pulled forward on the trailer.
The engine was then lower and towed into the garage.
Second engine ready to haul to the garage.
Both engines and one drive completely removed.
Daughter Kirsten helping with pulling the fuel tank.
I did have to cut an angle on the stringers just ahead of the motor mounts to remove the fuel tank.
The shape Sea Ray built into it fell 2 inches short of allowing the tank to be removed.
The cuts allowed the tank to roll back and be hoisted out.
Here you can see the angled cuts made to the stringer for fuel tank removal - pic taken after the project was completed.
My other helper - Cedar
Engines in the garage - good time to do some basic inspection/repair.
Now emptied out, the frame was turned, extended and used to cover the boat for the winter work.
My early winter working conditions.
Now the messy work begins:
Digging out and removing the old rotted transom was a messy project.
Most important item needed is a good respirator - you do NOT want to be breathing the heavy amounts of wood and fiberglass dust.
What's needed: Respirator, Fans to remove the dust, Circular saw, 4 or 5 inch grinder, Sanding wheeels, Chisels, Hammer.
Here is my cleaning process with pics following:
First I marked where I wanted to cut the inside transom skin with a straight edge.
Then set the circular saw about 1/8 of an inch shallower than the total thickness of the inner skin and wood core.
On the inside of the boat I cut the periphery of the area to be replaced with the circular saw and removed the inner fiberglass skin.
Any rotted wood was then dug out using chisels, screwdrivers, whatever I could reach with.
The remaining "good" wood was then ground out using the 4 inch grinder. I tried everything and found "sanding" wheels worked best.
Save the clean sanding dust to use as a "filler" later on.
A thorough cleaning was done to ensure the outer hull was fully cleaned of the original transom wood on the inside.
The rotted structure on either side of the boat was also cut-out and cleaned using the 4" grinder.
First circular saw cuts to remove center section of inner transom skin exposing extent of rotted wood.
Additional cuts were made to remove the entire transom core.
Thoroughly cleaned / removed transom and side structure.
This is the best wheel I found to use in the grinder for both removal and cleanup of the existing wood and inner side of the outer hull.
Time for the new stuff:
What's needed ?
Marine Grade Plywood
Epoxy (does not get brittle like polyester's and bonds better to surfaces)
I ended up using (5) gallons at about $120 per gallon
Fiberglass Cloth
I used 11 yards of Bi-Lateral cloth and 14 yards of 10 oz plain weave
Measuring Buckets
Mixing Buckets
Paint Sticks
Lay-Down Roller - aluminum (helps set cloth and remove bubbles)
Pigment (for coloring of final layer)
8 foot 2 x 4 - qty: (4)
Threaded rod - qty (4)
Nuts and Fender Washers - qty (8) each
Fiberglass Antenna Sampler
Trim Head Deck Screws - 1 1/4" long, Stainless Steel
Big Question - How much Epoxy / Resin do I need ?Epoxy (does not get brittle like polyester's and bonds better to surfaces)
I ended up using (5) gallons at about $120 per gallon
Fiberglass Cloth
I used 11 yards of Bi-Lateral cloth and 14 yards of 10 oz plain weave
Measuring Buckets
Mixing Buckets
Paint Sticks
Lay-Down Roller - aluminum (helps set cloth and remove bubbles)
Pigment (for coloring of final layer)
8 foot 2 x 4 - qty: (4)
Threaded rod - qty (4)
Nuts and Fender Washers - qty (8) each
Fiberglass Antenna Sampler
Trim Head Deck Screws - 1 1/4" long, Stainless Steel
I found out the general rule of thumb for "wetting" area of fiberglass cloth by one (1) Gallon of Epoxy / Resin is as follows:
1.5 oz. cloth - 40 sq. yards
2.5 oz. - 25 sq. yards
4 oz. cloth - 15 sq. yards
6 oz. - 10 sq. yards
10 oz. cloth - 6.5 sq. yards
18 oz. woven roving - 4.5 yards
24 oz. woven roving - 3.5 yards
Chopped Strand Matt by weight is 1 to 2
One (1) pound of Matt uses about two (2) pounds of Epoxy / Resin
What is Woven Roving ? Woven Roving is basically a heavy cloth.
These are estimates as there are many variables such as:2.5 oz. - 25 sq. yards
4 oz. cloth - 15 sq. yards
6 oz. - 10 sq. yards
10 oz. cloth - 6.5 sq. yards
18 oz. woven roving - 4.5 yards
24 oz. woven roving - 3.5 yards
Chopped Strand Matt by weight is 1 to 2
One (1) pound of Matt uses about two (2) pounds of Epoxy / Resin
What is Woven Roving ? Woven Roving is basically a heavy cloth.
The thickness of the Epoxy / Resin - thinner covers more area.
Application surface - bare wood will soak up and increase the amount needed.
Check with your supplier when purchasing. They can get you close - I ended up needing an extra gallon as I went along.Application surface - bare wood will soak up and increase the amount needed.
Bi-Lateral Cloth. Consists of a fiberglass matte sewn to a fiberglass cloth.
Two layers of this were used to cover the transom blending out onto the floor.
Epoxy Used:
E-cast CCA EPOXY RESIN w/ #305 HARDENER
(5) gallons total
From Eastpoint Fiberglass Sales near Detroit Mi
Aluminum Lay-down Rollers
They work great for working out air bubbles and setting the cloth laminates.
I chose aluminum so they could be easily cleaned (before the epoxy sets) for future projects.
Bolt and Weep Hole Liner Material.
Antenna Sample Pack - assortment of 6 inch long fiberglass sleeves
From: Max-Gain Systems, Inc., 221 Greencrest Ct., Marietta, GA 30068
Trim Head Deck Screws - Stainless Steel
Installing the new stuff:
Step One was to cut the pieces of marine plywood to shape for the transom and side structure.
The transom required (2) pieces of 3/4 inch marine grade plywood laminated together for the 1 1/2 inch thickness needed.
When laminating I wet the one piece of plywood with epoxy, worked in (1) layer of 10 oz. plain weave cloth, wet the opposing piece of plywood and sandwiched them together. I then used a numerous amount of 1 1/4" long stainless steel "trim head" screws to pull and hold them tightly together. The screw locations were roughly planned as they were NOT removed.
Laminated Cross Section (cut-out from outdrive holes)
The Transom section needed multiple pieces to allow installation behind the stringers. In the photo below you can see how the the laminated transom pieces would overlap once installed.
All edges of the lamination were sealed with multiple coats of epoxy before installation.
Overlap Detail
Step 2 was to install the laminated transom piece.
The laminated transom piece was test fit.
(4) holes were drilled from outside the boat for the threaded rod, one near the top and bottom of both outdrive openings.
The (4) 2 x 4's were then match drilled (through the narrow side) to these holes.
Everything was removed and the inner hull was coated with epoxy and layered with (1) layer of 10 oz. plain weave cloth.
The mating side of the transom piece was then wet with epoxy, installed and clamped to the transom using the threaded rod and 2 x 4's.
Clamped Transom Pieces
Step 3 was installation of hole liners and filling of any "gaps".
Fastener and drain holes were opened up to match the chosen tubing size, being careful to NOT go thru the outer hull.
Fiberglass tubing was then cut to length and epoxied in place.
Gaps between the transom pieces and the hull were then filled with a thick fiberglass dust / epoxy mixture.
Holes cut for the trim tab supply line and fasteners.
Trim tab holes with un-cut fiberglass tubing samples.
"Lined" drain plug hole.
"Gaps" filled with fiberglass dust / epoxy mixture.
Step 4 was installation of the side structure and covering the transom pieces.
(2) layers of the Bi-lateral weave glass were used on the inside transom with one layer of the same glass on the side structure.
The first layer was overlapped onto the "floor" by about 8 inches.
The second layer and side structure glass ovelapped about 6 inches onto the floor.
Note: "WEEP" holes were added to the aft-most corners of the side structure and exsting stringers to allow water to drain. Fiberglass tubing lined these holes as explained earlier.
The Aluminum Lay-Down roller was a big help in working out air bubbles with this final glassing step.
I did have minimal air bubbles in the side structure areas but was extremely pleased with the transom area.
Transom glass work
Side structure glass work
It was too late once I started but rounding all the edges and corners would have helped.
Working out the air would have been much easier as the glass does not like to "fold" over corners.
Step 5 Put in the Outdrive Cut-outs and Fastener Holes.
All of this was done from the outside using the existing holes and cut-out in the outer hull as a template.
I first used a 2 inch hole saw to drill two holes at the top of each outdrive opening. The holes were drilled at a 45 degree angle - see pic below. This is for clearance of the steering arm on the inside when turning.
Then the big hole was cut using a jig saw following the existing cut-out contour.
Next I drilled the outdrive fastener holes perpindicular to the transom.
They do have a drill jig available for the outdrive holes and cut-out but I opted to save a chunk of cash and just use the hull as a template - it worked fine.
These holes were too close to the cut-out to allow use of the fiberglass tubing for a liner so I used a pipe cleaner type brush to apply multiple coats of epoxy to the inside of the holes. The Cut-out also recieved multiple coats of epoxy to seal-er up.
The final step was to mix the grey pigment with epoxy and apply a final coat to everything for a nice clean colored look.
The "angled" holes can be seen here looking from the inside.
Step 6 Put everything back together !
Be sure to replace the outdrive transom assembly Seals!
A nice clean difference.
No more hanging wires.
This was the biggest of my projects, am very pleased with the outcome and glad I tackled it.
Best of luck with your repair !
For more on this boats restoration see my full story thread: http://clubsearay.com/forum/showthread.php?t=23289
Last edited:
