Another transom repair question...where to cut?

iRich	Hi, I recently acquired a 17' crestliner that is in good shape but the transom is spongy around the motor mounts so it has to be replaced. I am not sure if I will use sea cast or new plywood and epoxy yet but either way I'm going to get all the wood out not just the rot. My question is instead of removing the whole top of the boat I plan on cutting each side about a foot up and just removing the rear section. Then I will repair where I make the cuts at when I put it back together as I am not worried about it looking like it is fresh from the factory. it is a 1975 btw. Is there any reasons why this won't work and has anyone done it this way before? Thanks, Rich	2002-08-10
speed29668	That is similar to the way I replaced mine. I simply went along the edge of the entire transom and took the fiberglass off as one big piece. Leave about a 1-1/2" margin all the way around to create a pocket. Fit your plywood back in by using two or more layers epoxied together to achive thickness and by using two separate pieces, one for the right side and one for the left. Make them meet at an angle and cut the edges so they overlap. Remember overlapping can be done because you are using multiple layers of wood on both pieces. I also created a backing plate on the inside of the transom by cutting another piece to the general shape of the inboard side of the transom. I drilled holes and counter sunk them on the outer wood of the transom and inserted bolts from the outside all the way through to the inside piece of wood. The holes for the bolts were filled in with epoxy and made flush with the rest of the plywood. Everything is still epoxied together in the normal fashion; the through-bolting is there as an extra margin of safety. The outer fiberglass is epoxied back on and the edges were grinded down and widened and fiberglassed back together. Or you can use seacast, but that is an entirely different procedure.	2002-08-10
hw8478	A couple of years ago I had the transom replaced in my 23' Wellcraft with twin SeaDrives. They pulled the engines, cut and removed just the gunel and floor about 3' foreard of the transom. This gave complete access to the transom without having to cut the hull itself - which I did not want done. I had them uses a glass composit instead of replacing the plywood part (don't know what it is called). Worked like a charm - better and stronger than new.	2002-08-11
Bob_VT	This is the seacast link and it has a few pictures. http://www.seawolfindustries.com/scusage1.htm Seems pricey but I would go with it based on the repair speed. You can do it in less than a day. Bob	2002-08-11
iRich	Hi, Well I have the old transom out...it was totally rotten. I still have a little scraping to do to clean up the original fiberglass. I'm leaning toward using 3/4" pressure treated plywood doubled up to replace it with. I was seriously considering using the seacast if I didn't have to disrupt the glass but it was easier to cut some away on the inside and replace it than trying to dig all that wood out. Besides it was only one layer of glass that didn't even cover the top and ends. I think my biggest concern now is putting the top part of the boat back on ...as in how to tie it back in with the rest and make it strong. I've been taking pics and will post them somewhere if anyone is interested. Rich	2002-08-11
speed29668	Rich, Go ahead and post pictures. Did you end up pulling the entire deck off?	2002-08-11
oldboat1	I'm not sure epoxy will adhere properly to pressure treated plywood (assuming you are going to bond plywood pieces with epoxy). Maybe other listers have had some experience. I've had good success using the method described in the post by Speed. There are a number of refinements -- drill holes around the edge of the transom when the project is nearly finished, for example, and squirt in expanding foam. The foam fills cavities around the edge of the plywood and is added insurance that water will not wick up into the wood. (You need to treat the edges with epoxy when installing -- also to help insure that moisture will not soak in.)	2002-08-12
SCO	I did similar to speed, but used drywall screws to epoxy pieces together then refit into the cavity then glassed (with epoxy resin) the entire transom piece to seal completely prior to reinstalling it into the boat. I also epoxied the aft skin back on prior to installing, could lay it flat on the plywood which was flat on the ground to avoid having to use screws or big clamps to attach it. My boat has a V transom, and prior to putting the transom back in, I thinly glassed the inside wall(at the eventual fwd face of the transom) to be able to hold liquid epoxy without without leaking out. After epoxying in the transom , I sealed with epoxy paste around the perimeter from the outside, then filled the entire V portion with epoxy from the inside with thin epoxy. In my case there was an 1/8 inch gap between the inside wall and the new wood transom where I could pour the epoxy in batches from the cut off bottom of a plastic coke bottle. You could see the epoxy fill level through the translucent thinly glassed inside wall, so I knew my progress as I filled, and now the entire V portion is completely encased with no voids to fill w water. The down side... took a long time and may be overkill. Can email photos if you're interested	2002-08-12
epresutti	IRich, Be careful with the pressure treated stuff, when you get it, it is very wet. This can cause your transom to rot from the inside out. I would shy away from that stuff and use something that is going to absorb the resin. Doug Fir plywood is probably your best bet. You can also use layers of 1/4 with a layer of 3/4 oz glass between each layer until you get to your desired thickness, this creates a very strong transom and is a little easier than thicker pieces (takes more glass and resin though). Beware the pressure treated stuff, unless you are sure it is completely dry. Hope this helps. Safe boating to all. Cheers. emp.	2002-08-12
epresutti	Forgot to mention, when I redid my transom, I used basically the same technique used by SCO, except I filled the gap first with epoxy resin mixed with a powder of fiberglass (result of the grinding on the boat, you can use any high density filler), the consistency was like peanut butter, I completely filled the gap so that when the transom was pressed in the goop would squeeze out to fill all the voids (about 1 1/2 in. wide by 3" deep) making sure the transom seated to the correct level and also that it was squeezing the filler out of the gap. I used drywall screws to hold things together (like a clamp) then removed the screws and filled the holes with epoxy. If you are going to leave the screws in, you may want to consider grinding the heads off so they won't vibrate as much and potentially create a spider crack. Hope this helps. Safe boating to all. Cheers. emp.	2002-08-12
oldboat1	I used drywall screws to hold the epoxied pieces in place, but left the screws in and went back over them with epoxy. They countersink easily into the plywood so they can be easily encased. Do a search or two on transom replacement or something similar, if you haven't already done so -- lots of good information.	2002-08-12
epresutti	Oldboat1, I was using the screws to pull the wood tight to the inside (existing glass) and also to hold everything tight until the glass completely set. The screws were exposed on the surface on the old glass. Your right if they are countersunk and glassed over there shouldn't be a problem. Safe boating to all. Cheers. emp.	2002-08-12
SCO	Actually, I was attempting to put the transom piece in like Ed did, but was using flour to thicken(works pretty well usually), and didn't make up enough of the epoxy though I think no amount would have worked with my mix as it was running out of the bottom. It was hotter epoxy(no time to do anything but proceed)and because it didn't hold like peanut butter, I had a problem. I originally put the inside skin on to hold the peanut butter consistency epoxy, and in the end it saved me when I didn't get the full thickness squeeze out bond like Ed described.	2002-08-12
iRich	Hi, thanks for the suggestions guys, all good info. I wouldn't have even attempted this project if it wasn't for this forum. Another question I have is what do I need to do the glass work and where is a good place to buy this stuff. I was wondering if there is anyplace online to order it and save money or just buy it at a local store. Thanks, Rich	2002-08-12
epresutti	IRich, You can order almost everything you need from West Marine (they sell several epoxies, West Systems seems to be the most popular) http://www.westmarine.com . I just called their 800 number and ordered. They are based in St. Petersburgh FL, it was 3 days shipping to where I live now (Granville, OH). I use to live in Palm Harbor FL, I have been to their warehouse, you can walk in and buy as well. They are a full supplier of boat building materials (heck you can order a 55 gallon drum of epoxy if you want, big shipping charge I would imagine). They have a full range of bulk glass and multiple types of epoxy in sizes from pints to pails to drums. Hope this helps. Safe boating to all. Cheers. emp.	2002-08-12
epresutti	IRich, Sorry forgot to mention, you are going to have to measure everything, height and width of transom, etc. Decide what core your going to use and how many layers. I used 3/4 oz. between each layer and Double Bias with Mat (XM) on the outside layers, covered with 3/4 oz for a good finish. Mat comes in widths up to 60 in. My total transom height was less than 35" so I was able to use 38 in. mat and bias. You will probably use at least 3/4 gal of epoxy. Get a gallon. Accounting for waste and mistakes (not that you will make any, I didn't , right.) Safe boating to all. Cheers. emp.	2002-08-12
crab bait	These guys gave good advice & are right on target.. listen close & do as they say.. you'll have a good boat for sure.. just one thing.. never use 'thin epoxy' by itself without thickeners as a glue to fill gaps or a filler... it just won't work... it's not made for that.. it's too thin...	2002-08-12
iRich	Yeah, I need to do some homework on the fiberglass stuff...never messed with it before. I need to repair a section of the floor also...I think I will practice on that before I do the transom. I have some pics online now if anyone wants to take a look.. http://briefcase.yahoo.com/bc/irich39/lst?&.dir=/Transom+Repair+Pictures&.src=bc&.view=l Rich	2002-08-12
epresutti	IRich, Went to your link, got file inaccessible? Not sure what the problem is. Please advise. Safe boating to all. Cheers. emp.	2002-08-12
iRich	Ed, It should be okay now. I had the private button checked instead of public. Rich	2002-08-12
Hawkeye1	Here are 2 links for good quality epoxy at decent prices. Depending on how you do it, how much and what weight cloth you use will determine how much epoxy you will need. I think 1 gal might not be enough to do a complete transom, even on a 17'er. I would go with the slow hardener to insure a good soak in and maximize working time. BTW, I like the 1/4" thick build up and overlap all seams way of doing a transom. I wouldn't use the treated for reasons stated above. http://www.uscomposites.com/	2002-08-13
epresutti	IRich, After looking at your pictures, I agree with Hawkeye1, you may want to do the 1/4 in. buildup. Looks like you did a good job of cleaning it up. If you use the slow set (as recommended by Hawkeye1) you can roll out each piece of 1/4 in. and press into the goop you have put in the hole. If you transom is 1 1/2 in. you will need 6 pieces. Because of the irregular shape of the whole (meaning bumps and dips in the existing glass) you may not be able to "jam" the last piece in, this is OK, you can double, triple the glass on the fifth piece to make up the difference. On my transom I actually cut out the outside glass (there are lots of opinions that this is NOT the best thing to do), I got excellent bonds to the inside glass so it is still very strong, I also left a 3 in. grove and had a good pocket. Got to run. Good luck. Safe boating to all. Cheers. emp.	2002-08-13
iRich	Hi, what do you mean by 6 layers of 1/4"? I was going to use 2 layers of 3/4" plywood. Also what weight cloth should I use on the inside? Thanks, Rich	2002-08-13
epresutti	IRich, Instead of the two pieces of 3/4 (which is fine), you can use 1/4 with glass between each layer. 2 pieces of 3/4in = 1 1/2 in, 6 pieces of 1/4in = 1 1/2 in. Same thickness. Its just that you have more glass and resin in between each layer. The more layers the stronger. On my transom I used 3 pieces of 1/2in to get my 1 1/2 inches. Its really your choice, 3/4 will work fine. I wanted more layers (stronger). Also the resin will penetrate almost all the way through the 1/4 if you wet both sides, which you will have to do, and you wind up with an almost completely composite transom (OK, the engineers will argue there is still 1 1/2in. of wood). I would put a layer of glass in between your 3/4 and use thickened epoxy, you will get a very strong between the pieces, by the time you are done you will be able to hit that baby with a sledge hammer. I would use 3/4 oz glass. Hope this helps. Safe boating to all. Cheers. emp.	2002-08-13
iRich	Ok, now I understand why more layers...makes sense to me. Now, did you use fiberglass mat or cloth? ! assume by 3/4 ox glass you are talking about the stranded stuff and not woven, correct? I am also replacing the rear part of the floor...stringers,(is that what they are called, run the length of the boat), are ok thank God, but the plywood about 3 feet up was rotten. Should I use the same material on the floor? Thanks for your patience, Rich	2002-08-13
Hawkeye1	Some of the stranded mat is not epoxy compatible. Yes you can use the same material for the floor. I did my floor with 2 layers of 1/4 luan overlapping the seems and 1 layer of heavy 17/08 over it all. I had right much support from underneath. Came out like a concrete floor.	2002-08-13
epresutti	IRich, I used mat. Mat is random fiber with a binder agent. It is the binder that may not compatible with the epoxy (as suggested by hawkeye1). The binder dissolves when the resin is added. Just make sure the mat you purchase is compatible with epoxy. I found that you can also put a piece of 3 mil plastic on a flat surface, wet out the glass, flip it over, wet out the other side to eliminate any dry areas, be careful not to go to crazy with the resin. Then roll the glass out on the piece you are working on in place. I used disposable 9in. foam rollers to roll it out. Make sure you have no dry glass. Very important (I say again no dry glass). Also make sure you roll all the bubbles out. Wal-Mart has boxes of 100 latex gloves (like surgical gloves) for about $8 per box, well worth it (I have gone through many pairs, once I mix a batch and roll it out, I throw away the roller, brush and gloves, makes interesting artwork if you let them all dry together). You can clean up with acetone, I suggest using as many disposable products as possible. It is really difficult (my opinion) to get brushes and rollers clean with acetone ($9 per gal). Foam rollers $1.30, brushes $0.87. I also keep a "box of rags" handy, you know the thick paper kind. That's about it, have fun. Safe boating to all. Cheers. emp.	2002-08-13
iRich	Here's an update on my transom project. I haven't had much time to work on it this week. Tonight I bought a piece of 3/4" plywood. It won't work because my transom has a bend on both sides and 3/4 doesn't bend to well even with relief cuts. So I guess I will listen to the experts and use 1/4" X 6 layers. Ed if you are reading this, when you did yours did you put the plywood in one piece at a time? I think that is how I will have to do it so I can form it, just wondering the best way to go about it. I did get the pieces cut for the portion of the floor I need to replace. I'm planning on epoxying both sides and all edges then putting them in place and covering with epoxy and fiberglass mat. I was going to use the 2-1 thin epoxy for laminating and covering the floor...will this also work for the inner transom wall that I need to rebuild or should I use the thicker epoxy? Thanks, Rich	2002-08-16
Hawkeye1	Use the thin stuff and thicken it with cabsoil or other thickeners. You want the thin stuff the wet the glass and penetrate the wood. You using all mat worries me a little as there are very few that are epoxy compatible. not to mention they are not that heavy. The biaxles are very good and strong for there weight. Roven is about 1/2 the cost of biaxles and would be my 2nd choice.	2002-08-17
iRich	Ok, I'm finally getting back to work on my transom. I am using 6 layers of 1/4" plywood. Do I need to put glass between each layer or can I just epoxy the plywood together? Also should I thicken the epoxy between layers or is it ok straight out of the can? I am using west systems epoxy. Going to go cut the plywood now and get everything ready. thanks for any last minute tips. Hope I don't screw this up. Thanks, Rich	2002-08-24
epresutti	IRich, I did mine in pieces, I did not put the entire piece together and then put in place. I put a layer of glass and the first 1/2 (I used 1/2 in, I know you said your are using 1/4) in place. Used screws to pull it tight to the existing glass (make sure you have that thickened epoxy filling the gaps. I continued the process, layer of glass, thickened epoxy, plywood, etc. Until all pieces were in place then held the whole mess together with 1 1/2 in screws until it was completely set. Removed the screw and filled the holes with epoxy. Have all your pieces cut and ready to go, spend time with the dry fit. Once you start the glassing process you have to keep going. Watch out! Working time gets short! Also, as Crab Bait said above, make sure you are using thickened epoxy if you choose to not put a layer of glass between each sheet (I used thickened epoxy anyway). Rolled out the sheet onto the plywood outside of the boat on a flat surface, coated the surface with thickened epoxy and then put in place, secured with screws from the existing glass side. Using screws will be a little tricky since you are using 1/4" plywood, you want to make sure the screws don't go through the plywood and create a "standout" for next piece. There are a several different approaches you can use, like putting two pieces together at a time outside of the boat. You should just get a plan in your head. How am I going to roll out the glass, how much resin do I mix at a time, once I have it rolled out, How am I going to get it in place and make sure everything pulls up tight. Then how am I going to keep it tight until everything sets. Hope this helps. Safe boating to all. Cheers. emp.	2002-08-25
iRich	I got the transom in place. I ended up only getting 5 pieces of 1/4" because I couldn't jam another in there. The problem in my case is that the transom is not perfectly flat across the back...it curves in a bit the last 18" or so on each end. So I put two pieces in with thickened epoxy and screwed it tight to the outer skin with drywall screws from the outside. After it set up for a couple hours I took out the screws and put three more layers in and screwed from inside to the layers already in place. I have one layer of 1 1/2 ox mat on the inside and plan on adding at leas two more, probably three to make up for not getting the last layer of plywood in. The mat is epoxy compatible. I have some 6 ox cloth too so I will probably do one final layer with that. After that the only tough part left will be putting the top back on. I cut the gunnels just forward of the splash well so I didn't have to take off the whole top. I plan to paste the edges back together with thickened epoxy and rivets and laying a couple layers of woven roving inside the gunnels at least a foot to either side of the cut. Think this will hold good or should I grind the top of the gunnels down a bit and lay a layer there also? Trying to avoid that as I have no idea how to finish the top off. Any other ideas are appreciated. Thanks, Rich	2002-08-25
epresutti	IRich, 12" overlap is fine, sounds like you have it under control. Make sure whatever you overlap is binding to is not gel coat, but bare glass, well sanded (80 grit), this will give a very good bond. I ground off any gel coat and paint that would be part of the overlap. Lay your glass out dry, draw a line around where it will stop and grind off all paint and gel coat. You don't need to grind the glass down, as a matter of fact you want it to maintain it's original thickness. As far as finishing, sand everything smooth and then you can use epoxy mixed with fairing compound to feather out the joints (kind of like using drywall mud), sand smooth and you are ready for finishing materials, Gel coat, paint, whatever you decide. Pettit makes a good product called easypoxy, 1 part goes on nice, use their undercoat as well. Hope this helps. Safe boating to all. Cheers. emp.	2002-08-26
seacast	Please check out our website http://www.transomrepair.com. Our staff can walk you thru transom and stringer repair step by step. Seacast is a user friendly product that even the most inexperienced person can use!	2002-08-28
suzukidave	Wow, I just wanted to say this is one of the best threads on a difficult topic I've ever seen on this board. Great work guys. You should get it published.	2002-08-28
iRich	Hi all, Here's an update on my project. she's going in the water this weekend. just got done installing the motor and fired it up...runs fine. It was a lot of work and I wouldn't want to do it again, but I sure learned a lot...mostly just get in there and do it. thanks to everybody for their help and advice...every bit of it played a part in the success of this project. I will post back on Sunday and let you know how she rides...Watch out fish... Rich	2002-09-05

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