transom damage, seeking wisdom

patrick and linda · Posted: Fri Apr 01, 2011 9:53 pm Post subject: transom damage, seeking wisdom

i'm rehabing a small 16ft fiberglass run-about. today i removed the 70hp johnson outboard, 2 stroke engine. while removing the engine, the lower right corner of the metal plate dug, approx. 1/4" , for about 2.5" into the transom causing damage. more than likely the transom has at least minor rot. nothing visible.
so, i'm not interested in replacing the transom but thought about repairing the damage and then adding a 1/4" ss, 24" x 15", metal plate across the back of transom and then installing another smaller ss metal plate on the inside portion of the transom. engine bolts would pass thru both plates securing engine. the new engine will weigh less, 40hp 4-stroke honda.
so, would this works?
i appreciate any and all advice given.
thanks
pat

rogerbum · Posted: Fri Apr 01, 2011 9:58 pm Post subject:

It seems to me that if it "mostly likely has minor rot" that you really need to find out how much rot and if it is truly "minor". If there is rot in the core putting a piece of metal on either side bolted through may not increase the overall strength. If there's substantial rot, the two pieces of metal will simply be compressing the rotting core between the glass and this might result in fracturing of the surrounding glass. Better to drill a few inspection holes to know what you are really dealing with than to cover the potential problem with metal.

patrick and linda · Posted: Fri Apr 01, 2011 10:17 pm Post subject:

thanks roger,
best access point for drilling holes in the transom, would be outside of the boat. i could randomly drill some pilot holes, checking for rot, i guess i should go both above and below the water line. if the transom is 2" thick, i guess i would drill maybe an inch in. i would imagine if shavings come out that's good, if dust comes out, it's rot. i will do this tomorrow.
thanks
pat

rogerbum · Posted: Fri Apr 01, 2011 11:10 pm Post subject:

Patrick - do you have access to a moisture meter? You might want to scope out the transom with that if possible. Also just rapping on the fiberglass with the handle of a screw driver can be somewhat informative - you should get a very solid ding. As for test holes, I'd drill them just below a couple of spots that might be possible sources of water intrusion - e.g. any through holes or cracks in the transom cap. If you don't have any rot, just fill with epoxy and call it good. Finally, my last piece of advice - seek Thataway Bob's advice!

Captains Cat · Posted: Sat Apr 02, 2011 7:08 am Post subject:

I'd either move to Florida or fly Dr Bob up there to assist you! Mr. Green

Charlie

patrick and linda · Posted: Sat Apr 02, 2011 8:54 am Post subject:

i did tap the transom with a mallet but wasn't able to determine much of anything. i'll try a screw driver and see if that's works better. today i plan to move to florida! no i'm not! if i had chalie's money i'd be able to do that, but i don't!
so, i'll try the tapping and also several pilot holes and see what happens. i called a fiberglass repair shop and they quoted somewhere between 1200 and 2000 for a new transom. if that has to be done then need to decide to do it or scrap the project, sell the engine and call it a day.
i agree dr. bob has great advice and if he views this post i'm sure he'll chime in,.
thanks
PAT

Captains Cat · Posted: Sat Apr 02, 2011 9:39 am Post subject:

If I had the $$ you thought I had, I'd be rich! Laughing

Why don't you dig out as much rot as you can, laminate 3/8 exterior plywood to the outside and inside, Fill all the gaps with epoxy from the top, fiberglass over inside and out and paint it. The transom will then be 3/4 of an inch thicker and very strong.

On edit, just looked at your pix again. May be hard to get up under that back deck to put plywood on. The outside is another story. If the inside "skin" is OK, may not matter.

Lots of work but a lot cheaper and quicker than other methods.

Remember, "Better is the enemy of good enough".. Very Happy

Charlie

patrick and linda · Posted: Sat Apr 02, 2011 11:01 am Post subject:

charlie, you are thinking much like me! that's not good!
this boat, if i keep it, will be used, more or less, as our dingy. will be limited use, kept in covered slip. so, i'm looking for maybe a quick fix even though not the best fix. this normally isn't how i do things, but replacing a transom is way to much work for a boat that has little value. i like your idea but the stainless steel plate is stronger and easier to install. you are correct, oh wise one, inside the boat, at the transom is very limited on space.
thanks
pat

patrick and linda · Posted: Sat Apr 02, 2011 1:33 pm Post subject:

bummer! did a quick rot test by using a 11" plastic wire tie. using the bolt holes as asess points i put the wire tie in to see how far it might go. went in all the way, down and then to starboard as well as port. same results for each test. our local waste collection company will take the hull for about $40. i will sell the engine and control assembly, as well as the trailer and hopefully break even.
lessons learned, check the transom before stripping the boat, patching and sanding all screw holes.
thanks guys for good sound advice.
pat

Captains Cat · Posted: Sat Apr 02, 2011 3:14 pm Post subject:

Hey Pat, insure it for about $2500 (agreed value) and take it for a short spin in some deep water until it self destructs. Be sure to wear a life jacket and have Linda follow you in the big boat. You know how easy those insurance guys are to fool!! Mr. Green

FOR THOSE WONDERING ABOUT THE WISDOM OF THIE STATEMENT, I KNOW PAT IS IN THE INSURANCE BUSINESS AND WOULD NEVER DO THIS, NEITHER WOULD I

thataway · Posted: Sat Apr 02, 2011 3:15 pm Post subject:

Replacing the transom may not be as hard as you think. There are several ways. One is to take a fine kerf skill saw and saw all around the outer edge of the transom--remove the outside fiberglass. Then remove the tooth picks and rot which are left of the core. You can then drop in two pieces of 3/4" plywood, and totally encapsulate this with resin--use mish mash of epoxy to bed it in, and finally put the old glass back on the outside. (with epoxy between it and the plywood--use bolts to hold the whole thing together--as the epoyx sets up. The three latter steps are all done at once, and go fairly quickly--then bevel the edges of the cut, glass tape/mat in the area which was cut, and then fair and gel coat--fill the bolt holes, and you have a new boat. (sort of--but the transom will probably live another 50 years). You can use Cosa Board instead of the plywood, you can laminate 3 pieces of 1/2" if it is easier.

The other way, would be to cut the top open, and pull out all of the wood in the center. Then pour in "SeaCast". Material and instructions here:
http://www.transomrepair.com/catalog/ might cost slighty more than the plywood, but it does work and is good "forever"......I might go this way with that boat.

I have personal experience with the metal plates....what happens is that transom fails out further!

[/quote]

patrick and linda · Posted: Sat Apr 02, 2011 3:35 pm Post subject:

thanks dr. bob
good advice as always. i like the idea of simply pouring liquid down the void and having it fill in and harden. i guess since i have decided to scrap the boat, what damage could i do if i remove the top part of transom or for that matter cut the whole thing out. i did read that if cutting the transom out i should leave at least 3" of the corners and bottom intact.
thanks again
pat

thataway · Posted: Sat Apr 02, 2011 6:24 pm Post subject:

I wouldn't cut the entire transom--leave the inner layer of glass--there are some who say leave the outer--and if it is easy to get to the inner, that is a good idea. We redid a Grady White 20' and left slightly over an inch around the outside of the back.

On the other hand, we cut the entire transom out of our Cal 46--and it didn't go "sprong"-or move a mm! We left 3" around the outside, and then set the new transom, with a swim step and stair case cut back into the new transom--partly to get a 46 foot boat in a 45 foot "live aboard slip". It was a solid glass transom and weight was over 300 lbs--the plywood replacement (covered with glass) was about half the weight.

patrick and linda · Posted: Sat Apr 02, 2011 9:09 pm Post subject:

well doc,
not good news, the transom has extensive rot. the boat has been in my garage, at the lake, for the past 6 or so weeks. i was able to pull back the outer skin and look down inside. wet and spongy! my new plan will be to draw lines, 3" over from the corner ends down to about 4" following the bottom of the transom. then use a roto zip to cut the outer skin off. i could use the cut out as a template for the new plywood section. have to see what happens at that point. i'm telling myself i've already conceded to scrap the boat so if it's more than i want to take on, no problem. i can only work on the boat every other weekend, as the boat is at the lake.
you probably already know my wife and i spend a lot of time at the gym. i recently had elective surgery, healing is going well, my wife took great care of me and now i get to do the same for her, as she tore her acl working out and is having surgery this coming thursday. lets get all the crap over before boating season starts!
thanks again and i'll post for more advice as problems worsen.
pat

patrick and linda · Posted: Sat Apr 16, 2011 7:00 pm Post subject:

so, i never seem to have enough time to do everything that interest me. probably the same problem every one else has.
regarding the rotted transom, i have the necessary tools, have the skill and you guys to complete the rebuild but don't know where the time will come from to complete the project. i don't have much money tied up in this thus far, but a considerable amount of hours. everything has been taken off, all screw holes and nicks have been filled and sanded.
so, here's the deal, i have decided to scrap the project, sell the outboard for just about what i have invested.
as luck would have it, a 2003 boston whaler 170 montauk, merc 90hp, 2-stroke outboard came up for sale and i bought it. sea ray of cincinnati is our local boston whaler dealership, they also service my sea ray, so i had them service the outboard, check the compression, which they did and all three cylinders checked out at 105, i also hired a local fiberglass repair shop to take care of any nicks, plus epoxy the hull as well as apply bottom paint. so now i have more time to drink cold beer and think about all the work i got out of.
i appreciate the responses. i owe each of you a cold beverage, so let me know when you're in my area!
thanks
pat