Transom Repair Advice needed

[SCO]

Re: Transom Repair Advice needed

The Seacast is attractive but I am going to use exterior plywood because I know how to work with wood and can get all the materials locally and be finished this weekend. Trust me, nobody is going to want this 30 year old trihull 10 years from now so in this case seacast is overkill. I am reasonably certain that I can properly rebuild this transom with wood and get another 10 years min. It is clear from inspection that the water intrusion came mostly from the lower mount holes of the engine. Who knows how they sealed these when new, but I am thinking I will bore all through holes oversize, seal w epoxy and even glass w epoxy resin inside the holes, then fill holes with epoxy then rebore to the proper diameter. <br />sho305, you could be describing my transom. By getting up under the splashwell, I was able to see where the wood portion of the transom was by the thickness.

 

[tnt460]

Re: Transom Repair Advice needed

take the deck off you can cut it a few feet up and just remove the back be sure the boat is sitting straight and level when you take it apart so the boat wont twist

 

[SCO]

Re: Transom Repair Advice needed

Since this thread was bumped up, Ill update, but project not yet finished. I left the deck on and cut the aft skin of the transom around its perimeter and exposed the whole transom. I couldnt get it to come out in one piece. Thought Id made a mistake cause it was pretty solid but I took it all out flaking off layers with a big screwdriver and hammer (like using a chisel). I found plenty of powder soft rot in the middle layers caused by water at engine mount holes, and port side rot from water between the transom and aft transom skin that got in at the top of the transom on the outside. It took about an hour to get all the old wood out, maybe 2. I marked4 reference points on the glass after getting out all the wood(top bottom right and left), and took measurements from these points to the various corners of the transom then made a paper template, tested it to be the right fit and taped it to 3/4 ext plywood. Will cut it and check fit tonight, then use wood template to cut a 2nd piece and epoxy together, glass the whole thing, epoxy in place fitted to the stringers then drill holes for drains and mounts, glass inside of holes, fill w epoxy then redrill.<br /><br />Djohns, if you are still following this, do you think it overkill to glass the transom prior to putting it back in the boat vs painting several coats of epoxy on? <br /><br />One mistake. I measured the transom limits after chipping out the old. I should have done it prior to removing the transom. I wonder if the hull has squashed down some now that the transom is not there to support it. It is surprisingly flexible. I didn't think about that. I am going to have to do some work now to make sure the hull shape is not compromised.

 

[speed29668]

Re: Transom Repair Advice needed

Hey guys, I have a question about reglassing the outer piece of fiberglass after replacing the transom. I am doing the exact same thing as SCO on a 17 ft Glassmaster. I took off the outer fiberglass in one big piece using a power saw with a thin blade leaving a small margin on all sides. What is the correct method for reattaching the glass after the wood is replaced? The cuts are very narrow, between 1/16 and 1/8 of an inch wide. Can I fill these in with thickened epoxy? Or do I have to grind the gaps larger and fill them in with fiberglass cloth and mat? How large of a gap has to be made if I have to use mat and cloth? Thanks.

 

[oldboat1]

Re: Transom Repair Advice needed

For what it's worth, when I did my boat, I filled the crack (probably about 1/8 inch wide) along the perimeter of the cutout with thickened epoxy (I use sawdust), and that worked fine. I both epoxied and screwed the fiberglass piece to the epoxy-encased plywood, countersinking the screws (used drywall screws). I then covered the screw holes with thickened epoxy. As a final step, I drilled holes all around the edge of the transom and squirted expanding foam into the voids -- worked well, coming out of other holes so I could see the progress. It also forced out some residual water along the way, and I thought I had everything completely dry. The point was to keep all moisture away from the wood, particularly the edges, to the full extent possible. The expanding foam filled most of the drilled holes, but I epoxied over them to be sure.

 

[SCO]

Re: Transom Repair Advice needed

The transom was squashed. I proped up the stb and port edges of the aft hull bottom and the transom reassumed the design shape.

 

[sho305]

Re: Transom Repair Advice needed

Just finishing the transom on the 16' Bayliner, not 17'. I did it from the outside, but to do it again I would separte it or cut out the splash well. Gravity has a great affect on epoxy resin and is best pured *down* into a mold for sure.<br /><br />I left about an inch of glass in the inside to fit the wood to, and there was little glass inside that remaining. I dug out the rotten stuff with a chisel and my foot. I epoxied the wood after fitting, and matted the inside side of it. I epoxied the existing splash well and edges and screwed it in there wet.<br /><br />Then I matted the entire inside and beefed up the edges. After that I drilled and countersunk the old shell, and after sanding and repairing the old piece I gooped it up and screwed it on. I widened the seams and matted them some, then made holes in the top and inside and poured epoxy in all the voids. I put a loop of paper in the drain hole to hold it in. I had to mat a lip on the top of the transom so I could pour it full.<br /><br />Filling the seams vertically was work and I finally resorted to some Duroglass to smooth it out, but it is hard to sand. Was afraid to use a poyester bondo-type filler.<br /><br />Have only to get some gelcoat now to make it last, as I am afraid paint will have problems if left in the water. There may be some sanding marks in it if you look closely, but the shape is good and it should look ok from 6' or more away. I may build up the gelcoat to get rid of most of it.<br /><br />Pouring the epoxy in from the top is the only way to go here if at all possible! Even cutting the splash well out would leave two seams to fill on top; less than the transom. Then you could gut it from the inside easy, mat the inside, then pour it full. Your seams would be above the water line too. The only fiddling would be fitting the splash well to the new transom, as in this boat they are two pieces.<br /><br />I figure over 100 hours it this first time effort, but I did many other repairs to it such as rubbing it out and fixing seat frames and floors. Clearly a poorly paying adventure, but will make for much faster going in the future. That is what you get with a $200 boat.<br /><br />Now, how do I seal the motor bolt holes so this does not happen again?

 

[SCO]

Re: Transom Repair Advice needed

sho305,<br /><br />re motor holes, I can tell you what I did finally. I over drilled the holes,filled any voids in the wood( inside the new holes with epoxy and epoxy paste as needed) then after dry rat tail filed some,repeated as needed, cut a swatch of fiberglass fabric to size, wet the inside of the hole well with epoxy, then rolled the dry swatch into a small tube and let it unfurl in the hole. Make sure it is completely wet and touch up inside as needed w epoxy then let it dry. Next is to fill the holes with epoxy then redrill to the correct size. Then I painted the inside( with epoxy) a few times to make sure it was well sealed, and rat tail filed as needed to get the bolts in. You should have an all epoxy border hole. Mine came out about 1/8 inch or less thick from the inside of the hole to the wood The tough parts are drilling and redrilling the holes in exactly the correct place. I placed the motor on the transom, made sure it was flushly and correctly mounted then marked the exact centers with a center punch( I eyeballed this). Before drilling any holes, mark a larger circle around each hole with a compass on the transom so you can refind the exact hole centers with a paper template after you drill and refill the hole with epoxy. To drill the holes, I first drilled with 3/16 or so I think, whatever looked right at the time, to act as a pilot for the bigger hole to keep the big drill from walking. I made sure the drill was perpendicular to the transom surface( I did this by eyeball checking straight down and from the side). For the final engine installation, I used 3M 5200 to seal it again.

 

[Davidandkerrie69]

Re: Transom Repair Advice needed

I've been through replacing a rotted transom on a 14.5' stilleto. I cut off the back top-deck to gain access from the inside and left the outside skin. The transom wood was like compost. There was over 70 holes in the transom from various engines, pickup tubes etc.<br /><br />I have never fibreglassed before and found the whole thing not all that hard to do. I underestimated how much glass / resin went into the job. I'd say I used 20 litres of resin, 3 litres of epoxy and 20 metres of glass mat. I did the floor too.<br /><br />It is a very messy job, lots of dust. Use a diamond blade in the angle grinder, it cuts no effort at all. Watch the depth when cutting the floor out. I under estimated the depth and went straight through the hull!<br /><br />The top deck was a little difficult to get aligned and glued back on. I had to push out the hull sides with timbre and car jacks as the hull had caved in slightly with no top-deck supporting it.<br /><br />The job took all of winter to complete. It was very rewarding and is stong as steel. My new Johnson sits proudly where the old Merc was hanging on by a makeshift alloy plate. I saved around $1500 doing it myself!<br /><br />I read up as much I could on fibreglassing before I started. Go to a fibreglass place and pick up as much info as possible on fibreglassing. There are some excellent manuals from epoxy suppliers that show how to do repairs. I used epoxy to bond the new transom to the old skin. Used epoxy and woven mat in the high stress areas on each hull side, floor to transom joint. The back of the transom, bilge pit and floor was all done in resin, mat. I made it pretty thick in the joint areas. <br /><br />Send a post if you want to know specifics. I took plenty of photos if your interested in seeing each step.<br /><br />Goodluck.<br /><br />David

 

[BillP]

Re: Transom Repair Advice needed

I'm on my second floor/transon project now. Both are old 60s "classics" with splash wells and no liners. <br /><br />On the first one I left the outer skin untouched and cut the splashwell out to fit exterior ply for the transom. The seams were filled and painted and you can only see the joint by looking under the deck. Taking the deck off was too much work and I didn't want to deal with a flexing hull. I used polyester resin and the boat is still going strong 15 years later.<br /><br />The difference on the second boat is I am also replacing stringers and using pt wood thoughout...stringers, transom, floor with vinyl ester resin.

 

[newDIYer]

Re: Transom Repair Advice needed

I am currently replacing my floor, stringers and transom for an early 70's boat. I found the job to be easier by seperating the hull and deck sections. Takes a couple of hours to seperate and at least 3 men or a good hoist to lift the deck off the hull (on my 16 footer with a fiberglass molded bow and the windshield removed). I have a I/O so I also hoisted the motor out.<br /><br />After removing the old transom I sanded the rear fiberglass to clean and rough up the area. I then wiped it down with acetone (be sure to follow all safety precautions). I then trowelled on polyester filler (1/2 gallon per piece on mine) with a 1/4 notched trowell. I clamped in place and let set overnight. The next day I then put the second piece of ply in using the same process. After this piece set I glassed in woven roving around the edges of the transom (6 inch on transom-6 inch on boat). I then glassed over entire transom with mat. First time I had ever done this. It was not hard just takes a little time.<br /><br />My boat used the shoe box joint (hull to deck) and I had no problems. Just make sure the new transom with glass is not thicker than the original or you might have problems putting the deck back on. I followed Jim Anderson's book called "Runabout Renovation" and it was right on with very practical information.