Can I repair the transom this way?

adamjr

Petty Officer 1st Class
Joined
Jul 23, 2009
Messages
272
I have a 1972 Cruisers Inc 18.5 foot cuddy cabin. I have some rot in my transom. Well, it seems like a lot of rot in my transom. The way the boat is constructed, the cap extends all the way to the floor. I haven't taken the rub rails off but I would not be surprised if the boat is one single lamination of fiberglass. With that said I do not want get involved with the amount of cutting and later refabrication it would take to reattach and finish the cap to the rest of the structure.

I looked at the SeaCast web site and after taking measurements the 20 gallons I need are a little more then I can afford.:eek:

This leaves me with needing to remove the transom. As much as I would like to do this from the inside the inability or lack of desire to remove the cap would make this impossible. The interior design also makes it difficult because the way the floor is constructed there is a channel about 2 foot wide that runs down the center of the boat to the cabin and the floor is raised the entire length of the boat on both sides and this goes straight back to the transom.

I am left with wondering if it is feasible to remove the rear lamination and remove the plywood that way. Then I would have to taper grind the hull sides and bottom on the outside in order to re-glass the back. If I did it this way I could replace the entire transom. I would also rough and scuff the inner hull skin so I could bond the transom to it.

As far as materials I see a lot of people are using poly resin to do transom repairs as well as other glass repairs. According to a couple of sites I have looked at (all sales sites) nearly every one says that for bonding new glass to old glass you have to use epoxy resin only. Have any of you used polyester resins instead of epoxy without incident following the repairs? If so how long ago were the repairs made with not having problems occurr. I ask the resin type question for the obvious reason that the epoxy is double to triple the poly cost depending on where you source it from.

Finally who has the best prices on the proper resin for the type of repair I am writing about?

Thanks in advance.

Adam
 

RICHARD5

Petty Officer 2nd Class
Joined
Aug 8, 2009
Messages
150
Re: Can I repair the transom this way?

Need pictures if you want really accurate advice.

Aircraft Spruce is my source of choice. Their stock has a fast roatation (no old resin) and they are reliable for what I need. Saves me from wild goose chases. And they are less than ship chandlerys.

http://www.aircraftspruce.com/menus/cm/epoxy.html

An autobody vendor would have what you need but probably won't sell to the public. An autobody shop may or may not deal with you.
 

RWilson2526

Master Chief Petty Officer
Joined
Jul 23, 2007
Messages
810
Re: Can I repair the transom this way?

You could do it from the back if you have to. It is recommended by the person that did this one to leave enough flat surface around the edges to get a strong bond to the existing.

ImportantSkin.jpg
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,174
Re: Can I repair the transom this way?

I use polyester resin exclusively, I'd use epoxy if it wasn't so expensive.
Aircraft spruce is top notch, top price too.
I get my cabosil and cloth from them, its premium quality stuff.
Although I prefer the speed of poly resin over epoxy.

Get my resin from these guys, always fresh. $33 gal.
http://www.fiberglasssite.com/servlet/the-74/Premium-Polyester-Resin-1/Detail

I have never seen a properly prepared poly resin joint fail, never.

I think your calculation on the seacast is WAY off, I have a bigger boat and 2 buckets left me with enough to re-core my glass deck on a 20 footer.

Heres what I would do if I were doing mine again ( God I hope not),

cut the top of the transom off with a sawzall w/ fine tooth blade, then elec chainsaw the transom out ( see the video on seacast site) but use nidacore instead, its half the cost of seacast.
 

a70eliminator

Captain
Joined
Sep 9, 2007
Messages
3,688
Re: Can I repair the transom this way?

I holowed mine out and poured it full of polyester resins, I used a whole bunch of fibergalss rods about 1/2" diameter and placed them like rebar everything is good boat mostly just gets used for fishing.
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: Can I repair the transom this way?

I'm moving this over to the Restoration forum. You'll get a lot more help there and it is where it belongs. Good luck!!!
 

adamjr

Petty Officer 1st Class
Joined
Jul 23, 2009
Messages
272
Re: Can I repair the transom this way?

I'll post some pics later but it looks like Nida Core pourable transom repair system is the winner.

There is some damage at the bottom of the transom area where the outer transom skin meets the hull. I think my plan of action is going to be to grind away the bottom 3 or 4 inches of the outer skin and grind about an 8 inch taper up the skin and under the bow. Then I will chip out like what was shown in the SeaCast video and allow the chips and chunks to come out of the area I will have ground off. Then I will make a short piece of plywood (height wise) to make the contour of the hull/transom mating area and screw it to the hull after coating it liberally with mold release wax. That way I will have a form over which to make the hull repair. I'll put a couple of screw eyes through the top of the plywood form so after I make the repairs I can just pull up my form and then pour the compound.
 

adamjr

Petty Officer 1st Class
Joined
Jul 23, 2009
Messages
272
Re: Can I repair the transom this way?

I'm moving this over to the Restoration forum. You'll get a lot more help there and it is where it belongs. Good luck!!!


Thanks. I wasn't really sure where to post it.
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: Can I repair the transom this way?

whoever did there transom from the out side was just wrong.....that is not how you do a transom....unless he glassed the heck out of it....then glassed over the whole back....then faired the back and then re gellcoated it...it is more prone to fail.....even if he did all that stuff....it would still be prone to fail.

the trick is to make the transom PART OF THE BOAT.

im sorry....but if you want to fix your transom by not doing work....sell the boat....you will need to get in there and cut out the old transom....that means at least cutting the top of the splash well or cap....and that is just to get the chain saw down there....

transom replacements are a long grind....expext a minimum from a noob at 40 hours....but triple that number to be accurate.

it can be done ....and when you are on your repaired boat....there is no better feeling in the world....but it will take time and hard work.

cheers
oops
 

adamjr

Petty Officer 1st Class
Joined
Jul 23, 2009
Messages
272
Re: Can I repair the transom this way?

I appreciate your input Oops. Your extension thread is an inspiration. I fully agree with what you are saying. I am going to HAVE to re glass the botttom of the transom. As the pics below show I will have to remove some of the lower hull to repair the delamination of the rear skin. Like I said I will be tapering my grind 8 inches out from where the cut is made. I am going to use epoxy resin to do the bonding because I want to be that much more sure. It will definitely be a part of the hull and not just a patch.

After looking over some materials I have decided to use the Nida-Core porable transom compound. I will remove the bad area first and then the transom core. I'll make a short transom piece as an inner mold for the bottom. I will also repair any bad areas and unnecessary holes made by the previous owner that were filled uselessly with silicone (not even the good stuff). Then when that is all done and fully cured I will pour the transom.

Here is just a forward on shot of the boat. I like it's retro styling in general. The cabin is pretty useless due to it's small size. I will probably re-work it to use it for tackle storage.

P9014788.jpg


You can see from this view of the port interior that removing the entire cap would be a pretty daunting task.

P9014787.jpg


This photo shows the damage at the port side at the bottom of the transom. I am not sure if the higher up damage is from a poorly repaired previous accident or just a part of the delamination.

P9014793.jpg


Here is a starboard view fromt the bottom. From the two pics you can see the delamination pretty much goes all the way across the boat.

P9014791.jpg


This one just shows some rot to the starboard side of the outboard under the trim cap.

P9014795.jpg


My guess would be that over time the core absorbed water through all the holes in the transom and it just swelled and split the hull.
 

Knightgang

Lieutenant
Joined
Oct 6, 2003
Messages
1,428
Re: Can I repair the transom this way?

With that much delm going on, I am sure that you have more damage inside than just the transom. I really think you need to tear into the back of hte boat, do the transom right and dry out the bilge and underfloor and replace stringers and deck as needed or in its entirety. You got more problems than just transom from what I see....
 
Joined
Oct 22, 2007
Messages
2,598
Re: Can I repair the transom this way?

Aircraft Spruce is my source of choice.

I used to deal with them when I was building a plane. Pretty high dollar IMHO. For glassing supplies for boats I use US Composites www.uscomposites.com . Good service, and their thin epoxy is nice to work with. Also look at their 1708 glass, great stuff for boat repair - conforms to corners amazingly well for such a heavy cloth.

The epoxy vs. polyester resin debate will probably rage on forever, I've done some reading on the subject and have decided that for my repairs I'm using epoxy. It has around 5 times the adhesion of polyester, which can be significant because in doing repairs we're dealing exclusively with "secondary" bonds (bonds made to already cured material). Plus we're likely working in less than pristine conditions, and epoxy is easier to work with. Also, epoxy is 10 times better than polyester in terms of water absorption. As far as cost, yes epoxy costs more, but in the overall picture of a boat restoration you're talking about an extra $100 or so.
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: Can I repair the transom this way?

i drive right by one of those boats every day......

i kinda like them.....somthing different.:)

ok.....from the looks of the pictures....i think its been dropped on its transom.
thats why the de-lam....and thats why the transom is rotten.

i agree with the preivous poster that says you might have a lot more rot than you realise....

thats gonna be a big job.

first of all.....you really will have to investigate the stringers and floatation..
there is no use doing the transom with nida core and have bad stringers and foam.

search core sample....you have to find some way of getting below the liner to check.

ok.....because of the de lam....your transom is gonna be a real pain to take out if it is not all rotten.....any pressure on the glass hull and you could tear it off.....so you will have to be real careful.....you might want to think of bracing the transom skin while you tear to old one out.

one more thing.....taking the cap off isnt as bad as you think......in fact....if you are doing a stringer transom....it could save you hours and lots of money as you can go poly and wood.......even nida core at 10 bux a squair is still really expencive....especially with poly. all you need to do is make a gantry and your in business !
you dont have a traditional floor in there as it is just more than likely the liner over foam.....that saves you a big chunk of time as far as the overall restoration goes..

so you have some investigation to do before its decision time....the work is dependant on what you find with the stringers.....

any questions....just pm me with the link

cheers
oops
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,174
Re: Can I repair the transom this way?

Looks like an old thunderbird trihull, neat boat.

With that keel damage I would cut the splashwell off, cut the deck off and re-do the stringers and transom from inside, patch the hull from inside first and just do a plywood transom. It'll be simpler and cheaper if you just commit to doing it from the start. Glass the deck back when you're done.

Pourable transoms are better suited to hulls that don't have that much damage. Once you get into rotten stringers its better to open it up and go with wood all around, wood is still good stuff in my book.
 

ezmobee

Supreme Mariner
Joined
Mar 26, 2007
Messages
23,767
Re: Can I repair the transom this way?

Pourable transoms are better suited to hulls that don't have that much damage. Once you get into rotten stringers its better to open it up and go with wood all around, wood is still good stuff in my book.

I agree with this statement from Jonesg. One of the main purposes of pourable transoms is ease of use. They are meant for boats with good strong glass. You chainsaw out the rotted wood, pour in the material and voila you're done. Yours needs so much extra work you may as well just go with wood and save your money. I properly sealed wood transom will outlive us all anyway.
 

VeroWing

Petty Officer 2nd Class
Joined
May 16, 2009
Messages
150
Re: Can I repair the transom this way?

I'm inclined to agree with previous posters saying that transom repair on your boat should be performed from the inside. With the amount of damage shown in your pics, there most likely is deterioration of "stringer to transom" connection, and this is critical if you want transom repair to last.
I am just completing an "inside" transom rebuild. I did not want to remove my top cap either, and there are ways of getting around this. Take a look at my detailed 3 page transom rebuild link below. It is definitly a lot of work, but I am confident this transom will last indefinitly, if taken care of, and is stronger than the original.

http://forums.bateau2.com/viewtopic.php?f=10&t=19949&start=0

Keep in mind that if you do transom rebuild from the inside, you can first, after removing rotten wood and cleaning fiberglass, repair cracks in bottom of existing transom fiberglass, both from the inside and the outside. Plus you maintain the existing integrity left in this existing exterior transom fiberglass. That means the critical joining and support of the port and starboard sides to transom connections.
I also recommend using epoxy resin. It is much stronger than any other. I purchased material for my rebuild from Boat Builder Central. Their prices were the best I found, and they have "how to" tips, and a large forum dedicated to boat repairs and boat building. Just to be clear, I have nothing to do with this company, other than purchasing my rebuild material from them, and getting guidance for my project. Below is their site.

http://www.boatbuildercentral.com/

If you need any info feel free to Pm me. Good luck with your project. Mike
 

RICHARD5

Petty Officer 2nd Class
Joined
Aug 8, 2009
Messages
150
Re: Can I repair the transom this way?

For glassing supplies for boats I use US Composites www.uscomposites.com . Good service, and their thin epoxy is nice to work with. Also look at their 1708 glass, great stuff for boat repair - conforms to corners amazingly well for such a heavy cloth.
Thanks for the link. I'm always looking for other vendors.

The epoxy vs. polyester resin debate will probably rage on forever, I've done some reading on the subject and have decided that for my repairs I'm using epoxy. It has around 5 times the adhesion of polyester, which can be significant because in doing repairs we're dealing exclusively with "secondary" bonds (bonds made to already cured material). Plus we're likely working in less than pristine conditions, and epoxy is easier to work with. Also, epoxy is 10 times better than polyester in terms of water absorption. As far as cost, yes epoxy costs more, but in the overall picture of a boat restoration you're talking about an extra $100 or so.
I hear vinylester is now the stuff to use. I don't know if it's a new product or not, I don't recall ever hearing about it til recently. Very near the strength of epoxy and all the good qualities of ester resin, including the price.
 

adamjr

Petty Officer 1st Class
Joined
Jul 23, 2009
Messages
272
Re: Can I repair the transom this way?

Sorry I abandoned my own thread. I value the advice and I have weighed my options. As far as Richard's question with regard to vinylester vs. polyester vs. epoxy the following link provides some good food for though.

http://www.redrockstore.com/resin.htm

Boiling it down if you'd rather not read it it says that when you are bonding to previously cured materials that vinylester is very likely to delaminate.

As far as what I am going to do; well, the season is almost over and I am running out of nice weather. I am going to cover the boat and seal it up nicely from the snow and re-start this project in the spring.

I wanted to remove the cap but doing that in it's entirety isn't going to happen. I pulled the rub rail and removed the joining screws for the cap to hull connections. The cap is glassed to the hull in many places. I will drill into the stringers to see what I get. If they are wet I will use a product like CPES or Git-Rot to repair them.

I will cut out the back portion of the cap that includes the splash well and remove the transom from the inside. The exterior design isn't very complex and I can make a partial mold out of aluminum so I will have something to glass against. Their are a few areas of the outer transom skin that will need to be repaired where holes were previously drilled for a couple of throug-hull ports plus where the support for the steering cable bolted to the transom is cracked. There was also once a swim platform mounted on the port side that a previous owner removed. All of the screw holes were siliconed, and not very well or with the good stuff.
 

HVAC Cruiser

Lieutenant
Joined
Sep 12, 2009
Messages
1,254
Re: Can I repair the transom this way?

I also have a Cruiser, only its a 1973 21' that had a bad transom..Oops is right about not doing it from the back, but I found out to late. I started mine based on someone elses recomendation (not from on here) to cut the back glass off 3" in. The one thing I did find with my cruiser is that at the transoms outer perimeter the glass is paper thin and very easy to go through thats probably why you have cracks, mine was the same, it couldn't handle the stress when the transom started going.

Cutting the deck off that boat is not that easy, its glassed into the hull in areas. The way I wound up doing it is by 1st cutting out the splash well which is fairly easy, just cut the cap by the side storage and remove the screws there under the rub rail , and the well comes right out. I can't tell good enough by your photo if those are white hatch covers or someone glassed over the fish bins in the deck. But in any case, the deck is laminated into the stringers on both port and starboard sides, in my case the wood was so soaked it delaminated. By those bins is where under-deck damage starts on these boats the foam gets water-logged and goes from there.

In the spring when you start your project, I hate to say it but your best bet is probably what I am in the process of doing, very carefully cut the deck out in sections gut the foam and rebuild it from the bottom up, stringers, deck and all. Although thats not what I wanted to do, one section of rot lead to the next.

Bill
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
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May 19, 2001
Messages
26,019
Re: Can I repair the transom this way?

Do you live in an area where there is freezing? That damage is more than likely from wet wood freezing and causing failure in the fiberglass.

I would pull the cap and do all the work from the inside...... this will also allow you to see what real shape the stringers are in.
 
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