What is the best approach to repair a Whaler Drive that is rotten?
BACKSTORY: I recently purchased a 1989 27 Full Cabin Whaler Drive boat from a long time friend out of Galveston, Texas. The boat now resides on its trailer near Freeport. The vessel is very solid with the usual crazing found on older Whalers.
My concern is the Whaler Drive. The engine mounting bolt washers are sunk into the fiberglass, and the fiberglass around the lower washers is severely cracked around them. There are also stress cracks aplenty, especially in the curves and contours.
The Whaler Drive does not have the central support bar. I' will have to machine one out of stainless bar stock. I'll also have to drill thru the Stern as the hole is not there.
My concern is repairs to the Whaler Drive itself.
This will be my second boat restoration; my first was my [1973--always use four-digits for years] Mako 17.
[I did not need to repair the] transom with the Mako, so this [Boston Whaler restoration] will be new to me.
27 Full Cabin Whaler Drive Repair
Re: 27 Full Cabin Whaler Drive Repair
The construction of a Whaler Drive is similar to the construction of the Unibond hull of the Boston Whaler boat. Repair of the Whaler Drive would follow the same methods as a repair to the Unibond Hull. For advice on repairs, see these articles in the REFERENCE section of the website. The REFERENCE section contains long-form articles on many topics related to Boston Whaler boats:
http://continuouswave.com/whaler/refere ... epair.html
http://continuouswave.com/whaler/refere ... tions.html
I have a 22-foot boat with a Whaler Drive. The boat has a single engine and there is no center support tube needed. I can offer the following observations:
To have a slight depression of the engine mounting bolt washers into the surface of a Whaler Drive is not particularly unusual. The bolts were probably over-tightened.
To have some stress cracks in certain areas of the Whaler Drive which in the mold were concave curved recesses is not particularly unusual. The gel coat layer tends to be too thick in those area and will exhibit some surface cracks.
Regarding soft or rotten wood in the embedded wood of the transom of a Boston Whaler boat:
Problems with wood rot in the transom of Boston Whaler boats are usually caused by poor installation of the engine mounting boats, and in particular the lower engine mounting boats on boats whose static trim causes the lower engine mounting boats to be immersed into the sea.
Restoration of the transom embedded wood is a difficult repair. In general, to replace the original wood the aft face of the transom laminate must be cut off. The rotten wood must be removed. New wood must be laminated to the hull. The outer gelcoat layer must be restored. And to accomplish this work the outboard engines must be de-rigged and removed from the boat. This is a serious project and should not be undertaken lightly. Before beginning a repair of this type, the presence of water and rot in the embedded wood in the transom must be established beyond any doubt and be established as have affected the entire transom area, not just small areas surrounding the poorly sealed engine mounting bolt holes.
There is a multi-part series of presentation on YouTube showing replacement of the embedded wood in the transom of a 25-foot. The series starts with this segment:
https://www.youtube.com/watch?v=4UOtdrxNX8U
To find other segments use these search results:
https://www.youtube.com/results?search_ ... ton+whaler
http://continuouswave.com/whaler/refere ... epair.html
http://continuouswave.com/whaler/refere ... tions.html
I have a 22-foot boat with a Whaler Drive. The boat has a single engine and there is no center support tube needed. I can offer the following observations:
To have a slight depression of the engine mounting bolt washers into the surface of a Whaler Drive is not particularly unusual. The bolts were probably over-tightened.
To have some stress cracks in certain areas of the Whaler Drive which in the mold were concave curved recesses is not particularly unusual. The gel coat layer tends to be too thick in those area and will exhibit some surface cracks.
Regarding soft or rotten wood in the embedded wood of the transom of a Boston Whaler boat:
Problems with wood rot in the transom of Boston Whaler boats are usually caused by poor installation of the engine mounting boats, and in particular the lower engine mounting boats on boats whose static trim causes the lower engine mounting boats to be immersed into the sea.
Restoration of the transom embedded wood is a difficult repair. In general, to replace the original wood the aft face of the transom laminate must be cut off. The rotten wood must be removed. New wood must be laminated to the hull. The outer gelcoat layer must be restored. And to accomplish this work the outboard engines must be de-rigged and removed from the boat. This is a serious project and should not be undertaken lightly. Before beginning a repair of this type, the presence of water and rot in the embedded wood in the transom must be established beyond any doubt and be established as have affected the entire transom area, not just small areas surrounding the poorly sealed engine mounting bolt holes.
There is a multi-part series of presentation on YouTube showing replacement of the embedded wood in the transom of a 25-foot. The series starts with this segment:
https://www.youtube.com/watch?v=4UOtdrxNX8U
To find other segments use these search results:
https://www.youtube.com/results?search_ ... ton+whaler
Re: 27 Full Cabin Whaler Drive Repair
Regarding the lack of an exposed center support brace between the hull transom and the Whaler Drive transom: omission of this support was a serious mistake in the original rigging of the boat, which I assume has twin engines, as would be typical on a 27-foot hull. If the boat has only a single engine, the support brace was not used.
I do not believe the support brace was a solid rod. I think it was a tube. You might be able to find one at a long-time Boston Whaler dealer who sold some larger boats. They might have one sitting around. You will need a dealer with a mechanic in his late 60's in order to remember what the support was for and why it was retained instead of being thrown away. So don't go to a dealer who just took on Boston Whaler boats 10-years ago and ask a 25-year-old guy about it.
There should be stainless steel caps on the Whaler Drive transom inboard face and on the boat transom outboard face that indicate the position for the center support tube.
Regarding the boat's history on being located in Galveston, Texas, from that mention I would infer the boat was used in saltwater. Generally saltwater does not cause wood to rot. Freshwater is the more associated with wood rotting. Also, 27-foot boats are often kept in the water and not trailered.
If the boat in question was kept in a dry-stack storage, and there was no center support tube, and the boat has twin engines, the Whaler Drive would have been subjected to some unusual stresses.
I do not believe the support brace was a solid rod. I think it was a tube. You might be able to find one at a long-time Boston Whaler dealer who sold some larger boats. They might have one sitting around. You will need a dealer with a mechanic in his late 60's in order to remember what the support was for and why it was retained instead of being thrown away. So don't go to a dealer who just took on Boston Whaler boats 10-years ago and ask a 25-year-old guy about it.
There should be stainless steel caps on the Whaler Drive transom inboard face and on the boat transom outboard face that indicate the position for the center support tube.
Regarding the boat's history on being located in Galveston, Texas, from that mention I would infer the boat was used in saltwater. Generally saltwater does not cause wood to rot. Freshwater is the more associated with wood rotting. Also, 27-foot boats are often kept in the water and not trailered.
If the boat in question was kept in a dry-stack storage, and there was no center support tube, and the boat has twin engines, the Whaler Drive would have been subjected to some unusual stresses.
Re: 27 Full Cabin Whaler Drive Repair
Thank you very much for the information. I should have mentioned that the vessel has twin engines. It has spent its time in the water in a slip. It was removed from the water when we had hurricane Ike, and has only been to sea once since then. It has remained on a custom Quickload trailer since. The boat is from St. Petersburg Florida.
I had to rebuild the trailer suspension in order to move it. The boat will eventually return to a slip when I am finished. I may have it professionally repaired due to the extent of work required. I assumed ( I know, not good) it to be rotten due to the severity of the cracks
along with the recessed washers. I have not yet taken a core sample of the inner wood. Again i assumed this based on visual inspection and from the countless forums I have read. I also plan on new engines. I don't want to revive the 1990 Yamaha Saltwater series 250's that are on it now. Parts are not easy to find for those engines.
I had to rebuild the trailer suspension in order to move it. The boat will eventually return to a slip when I am finished. I may have it professionally repaired due to the extent of work required. I assumed ( I know, not good) it to be rotten due to the severity of the cracks
along with the recessed washers. I have not yet taken a core sample of the inner wood. Again i assumed this based on visual inspection and from the countless forums I have read. I also plan on new engines. I don't want to revive the 1990 Yamaha Saltwater series 250's that are on it now. Parts are not easy to find for those engines.
Re: 27 Full Cabin Whaler Drive Repair
I would not consider the presence of a few stress cracks in curved portions of the Whaler Drive as conclusive evidence of wood rot for the entirety of the wood embedded in the Whaler Drive.
I would not consider a slight depression in the inboard face of the Whaler Drive transom in the gel coat laminate surrounding washers for the engine mounting bolts as conclusive evidence of wood rot for the 3ntirety of wood embedded in the Whaler Drive.
I would not consider a slight depression in the inboard face of the Whaler Drive transom in the gel coat laminate surrounding washers for the engine mounting bolts as conclusive evidence of wood rot for the 3ntirety of wood embedded in the Whaler Drive.
Re: 27 Full Cabin Whaler Drive Repair
Your time and knowledge are greatly appreciated. I Thank you again.
Re: 27 Full Cabin Whaler Drive Repair
Ditto, those are common on older Whalers and mechanics who don't know Whalers tend to over tighten the bolts. If you take it for a ride and the drive changes trim under throttle, you probably have a rotten transom.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).
Re: 27 Full Cabin Whaler Drive Repair
This is my first Whaler. I am very proud to own it. She is big and will be beautiful again. I am grateful to receive replys from the folks that know them best. This is a great forum, and I am Thankful to have found it. This particular Whaler is sentimental to me. I have spent a lot of time on it in my younger years, and have even spent the day hanging over its side. My wife has too. My daughter caught her first fish on it while my buddy's boy was eating the bait --I laugh aloud--. Thank you All!! I have a lot to go through so I will post more questions in the future.