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asboats2002

Transom Re-Coring Project

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Thought I'd report on my latest project, on "The Dr. Ann"    1975   R-236  Cuddy Cabin.  It's a project probably most people dread the thought of having to do.

I've owned this boat now for the last 23 years,  bought it from a guy that lived in a waterfront subdivision, but knew nothing about boats...…..  It's been a GREAT all around boat for me and I've done a lot of clean-up fix up projects on her over the years.  A couple months ago, my neighbor and I took her out to the river to try out a different prop.  Upon returning home and beginning to flush the motor, I noticed that the top of the Gil Bracket where it bolts to the transom had about a 3/16" gap …….  At first we thought maybe the bolts had loosened up an just needed some retightening....   Well, after checking it out, we realized that wasn't the case and that the transom core had to be bad !!  So I unscrewed the onboard battery charger inside the transom an procee3ded to push a small screwdriver into the hole to check the core...…  Ugh,,, immediately, I knew the result wasn't good.....

Decided if possible (Depending on how bad the core was )  to do a new pour in core, using  "Carbon Bond Transom Pour" product.   Decided on this product, since I had a gil bracket with a F-200 Yamaha hanging on it and wanted a product that had a Good Compression Ratio.   The comparison was   Carbon Bond ( a Resin product with fiber an ceramic sphere fillers)  against the Foam pour in products.    Carbon Bond has a compression Ratio of 3,895 lbs. per square inch versus the foam products of  700 lbs. per square inch.  Needless to say, I chose  the Carbon Bond product.

In the pics attached, you'll see what I believe was the Real culprit, that wasn't visible to me over the years, because it was hidden by the Gil Bracket top. Someone before me, must have had something screwed to the transom, under the bracket cover AND NEVER closed the hole when they removed it !!  So,,, every time the boat was put in the water, water went in the hole and wicked up the core.... Needless to say, and thankfully, it was completely rotten , ALL 8ft. wide by 34 inches deep.

The tools I used to clean all this out (it took my 3 days working a few hrs per day ) were;   Air Hammer, regular wood Spade bit on extensions, makeshift vacuum tube  (1" plastic pipe attached to my shop vac ) and a 1' drum sander on extensions with 60 grit sanding drums.   Since it was all rotten, it was fairly easy to breakup an then suck out, it just took a while because your working in the standard  1 1/2 inch core space.

I must say, the Carbon Bond was really super easy to work with, and poured thru the makeshift wooden funnel as they suggested.  The whole transom was filled to the top and took 17 gallons. The cost of the product was $800.

Now , the transom will probably outlive Me !!  No more rot  EVER !!

Hopefully, this will give anyone that may need to do this project, some insight on what to expect.  If anyone has any questions, feel free to reply and I'll do my best to answer the questions.

Don   "The Dr. Ann"   1975  R-236

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Love those "tools of destruction"!

Carbon core was definitely the best choice.  When I re-did my transom 12 years ago, there were only 2 pour-in-place transom products available; one was  a resin/chopped fiberglass mixture and the other was the predecessor to Carbon Core that was being used by the boat manufacturers.  Since I was going to change the transom to a full transom like your boat, a poured transom was not the best choice at the time since I was removing the inner fiberglass for additional strengthening.

I like the simplicity of replacing the wood with the poured material, though.  The transom on your boat looks real nice.  Gotta ask, though...did you re-locate the scuppers?  I don't see them.  Also, if they are in the transom, any issues with the back end sitting low in the water and if multiple people are at the transom water comes in?  If so, how do you deal with that?

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Yea,  It's always fun tearing it apart,,,,  when you can get to where you need to work ??????   1 1/2"  isn't that work friendly, if you know what I mean.....  That causes you to improvise the tools!  Whoever did the Full transom ( I heard it was a professional fiberglass boat shop)  did do it right,  2- 3/4" marine plywood with a sheet of 1/16" glass laminated in between them. That piece is what made it a little harder to get out, as I had to use the air chisel to break it into pieces before I could break up the wood to vacuum it out.

I would have been a much more work intensive job, if I would have had to do it like yours from inside removing everything to get to it, then putting it all back..

As for scuppers,  there aren't any,  whoever did the full transom, ended the floor about 6" from the transom and built in a small well across the transom, where the drain plug is.  I thought about trying to put scuppers in, but decided it was much easier to just put a small automatic bilge pump in there for any water that drained in there. Has worked fine for all 23 years so far, so I'm gonna leave it like that. That way, I don't have to worry about 4 people fishing in the back  an having water come in …..

I've attached some more pics of that area, so you can get the idea...    Also, whoever did the set up, only had some small square  SS pads as reinforcements for the top bolts holding the Gil Bracket, so while I was doing the work, I added the proper C-Channel, which is how that is supposed to be done, that way the load is stretched out across the transom where the pull back is.

Bottom hatches allow access to that transom area and the top hatches are a flow thru or circulating bait box.

 

Don

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That aluminum channel is the ticket for a backer.  I sometimes wish boat manufacturers would use the channel when mounting engines directly on transoms.  I have seen lots of large stainless steel fender washers that had belled over time since there is not really any strength to them.

Scuppers are a pain when you start changing the weight distrtibution around on the boat.  I knew I was on the limits putting a 30" bracket on the 2160 and was able to offset the weight shift some by having an extra large tub built into the bracket.  If I was to do it again, I would seriously consider raising the floor an inch...that would have eliminated 90% of my issues on water getting back in through the scuppers.  I now have a set of racquetballs with a rope handle that make a perfect plug in the scuppers.  The rope handle is yellow so it is easy to find.  I just tell anybody new to the boat if we take a wave over the bow, pull the plugs and let the water drain out then stick them back in.

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Did you try using one of the  Ball Scuppers ?  I have a friend with a 25' Dusky that has had them for like 25 years and they work very well for him.

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No - I had not tried them yet.  Was trying to come up with a way to get maximum outflow with as little as possible restriction.  I may end up with them, though.

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Just wanted to ADD something  I did during the project that made things a little easier when it came time to putting things back in the same place as they  originally were.

It also saved some time on finishing the project faster !!

My next door neighbor owned his own Refractory business for 35 years. They did major work at all the Refineries in the area, relining Cat Crackers an towers. This was a trick he learned which saved them a lot of hours and $$….

Since we were doing a pour in transom job, we removed the bolts holding the Gil bracket on and wanted them to go back in the same place.

So before pouring the Carbon Core in, we installed the bolts and nuts hand tight into the holes with washers on both side of the transom (inner & outer).

The trick was to tape a 1" paint brush to a stick that we could reach down into the core and coat the bolts with  "CRISCO" shortening for baking stuff. !!  

He said it works every time and perfectly as long as you spin the bolts an coat the whole surface.

He was 100% correct !!  After the Carbon Core cured, you could just take the nuts off and slide the bolts out,  No drilling new holes an maybe getting one off center... then re-install the gil bracket or your motor if that's the case and it will be exactly in the same place it was when you started the project !!

Don  "The Dr. Ann"  R-236

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Can't get much more high tech than Crisco shortening!  Sometimes the most basic thing is the best for some difficult things.

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