transom and floor replacement

SKIBUM1M

Chief Petty Officer
Joined
Jul 17, 2009
Messages
604
I have a 1990 15' larson all american 150 that I bought this past summer. The center of the floor was "soft" which I knew when I bought it but it was a good deal and replaceing a floor cant be that bad right? Well a couple weeks after buying it and getting my 1966 johnson 60hp running ok i pulled the soft plywood that was covering the soft floor in the center and found it was real soft so i made a temporary "better" patch job just to get thru the summer. It worked and I had alot of fun with the boat. Well now that the season is over it's time to get to work. I pulled the cap off the boat using my engine crane and pulled the boat in the garage to do the work. I used an air powered angle grinder to cut the fiberglass and pulled out the rotted plywood floors. I also noticed cracks in the transom so i investigated and found it was soup. so i cut the inner wall out and pryed the wood out. than I fiberglassed in a piece of laminate and cut a wooden backer so i can pour in seacast. I also spent some time here and there buffing out the side of the boat. ok that pretty much brings me up to where I am at. Sorry I havent gotten pics up to this point but I have been busy reading Oops's extension and now I want to document my work as he has. As soon as I figure out Photobucket I will post pics
 

SKIBUM1M

Chief Petty Officer
Joined
Jul 17, 2009
Messages
604
Re: transom and floor replacement

10-08-09007.jpg

Here is a pic of where she sits in my garage
10-08-09009.jpg

Here is where I cut a piece of laminate to the shape of the tansom and fiberglassed it in place (hopefully water tight)
10-08-09008.jpg

Here is where I will pour the seacast in. I like how the base under the swim platforms makes a nice funnel shape into the transom.
10-08-09013.jpg

The stringers seem pretty solid so I think I will just clean off the remaining floor from the top of them and seal the top of them with fiberglass.
10-08-09014.jpg

A good picture of the remaining floor which I havent gotten to yet.
10-08-09015.jpg

Ok here is my first question. There is thick foam on the sides which is covered on the inside with fiberglass. well alot of this had seperated from the sides of the boat and some i had to remove to get to the floor which went uner it. My question is how do I readhere it to the sides of the boat. I thought of using epoxy but will that eat the foam?
 

SKIBUM1M

Chief Petty Officer
Joined
Jul 17, 2009
Messages
604
Re: transom and floor replacement

10-08-09010.jpg

A better picture of where I had to remove the foam
10-08-09012.jpg

A Picture of where the foam has seperated.

The foam thruout the boat is amazingly dry and I dont think I will have to replace any of it as long as i can find a way to glue this stuff back on. after it is glued back on i plan to fiberglass the edges into the boat to waterproof it and make it so it hopefully wont seperate again.
 

SKIBUM1M

Chief Petty Officer
Joined
Jul 17, 2009
Messages
604
Re: transom and floor replacement

So I finally got back on the boat. I got 5 gallons of seacast and poured the transom and am now working on the floor. I built the inner transom wall with 2 layers of biax and polyester resin wet out on plywood covered with moldrelease. then sealed that into the hull and bolted thru all existing holes in the transom. the stuff got so hot while curing that you could barely touch the outer skin. now the transom feels rock hard and will never rot again.
 

timfives

Petty Officer 1st Class
Joined
Jul 30, 2009
Messages
382
Re: transom and floor replacement

awesome project, Curious as to why you used sea cast vs. plywood sealed with epoxy? always looking for perspectives, i'm in the process of doing my islander at the moment.

Keep up the good work!

Tim
 

SKIBUM1M

Chief Petty Officer
Joined
Jul 17, 2009
Messages
604
Re: transom and floor replacement

I used seacast because I never want to have to do this again. The previous transom was plywood in fiberglass but every hole in the transom alowed water to get in the wood and rot it. The worst invasion came from around the drain hole. With seacast even if water gets to the seacast it will not do any damage. I am using plywood covered on both sides with fiberglass resin so hopefully it will not rot in the future. If cost were not an option I would use seacast for the floors also.
 

SKIBUM1M

Chief Petty Officer
Joined
Jul 17, 2009
Messages
604
Re: transom and floor replacement

IMG00006-20091117-0133.jpg

I found out the seacast had to be sandwiched between layers of fiberglass. So I had to remove my form and build and install a fiberglass inner wall for the transom. The inner wall was made with 2 layers of biax and 1 and 1/2 quarts of polyester resin.
IMG00007-20091117-0133.jpg

IMG00011-20091118-2249.jpg

IMG00012-20091118-2249.jpg

I poured the transom then removed the plywood backing from the inner wall.
IMG00013-20091118-2250.jpg

After the transom was finished I finished removing the floor
IMG00014-20091121-1405.jpg
 

BobsGlasstream

Commander
Joined
Sep 11, 2009
Messages
2,128
Re: transom and floor replacement

SKIBUM1M,
Not much will eat the foam. You can use about anything you want to reattach it. I would recommend that you pour new foam myself. If you decide to reuse the foam make sure you seal it. The closed cell foam won't soke up much water by it will hold some.
My boat had the foam on the gunwales to and I'm just going to re-pour the foam. and then paint it.
Looks like a good project.
Have fun.
Bob
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,174
Re: transom and floor replacement

IMG00006-20091117-0133.jpg

I found out the seacast had to be sandwiched between layers of fiberglass. So I had to remove my form and build and install a fiberglass inner wall for the transom. The inner wall was made with 2 layers of biax and 1 and 1/2 quarts of polyester resin.


Not that it matters now but you coulda left the ply form in place and poured the seacast, then remove the form and glass an inner glass wall right onto the seacast, less work that way.

I made an inner wall from 1/2inch ply, I pre-glassed it both sides and sealed the edges, then poured the seacast and left the plywood where it is.
Transom is 3 inches thick now. I had to buy $40 longer engine bolts. duh!

Try contact cement to attach that foam again.
 

SKIBUM1M

Chief Petty Officer
Joined
Jul 17, 2009
Messages
604
Re: transom and floor replacement

I ended up using fiberglass resin to reattach the foam. the foam is in great shape and doesnt look like it has ever gotten wet since it has a fiberglass inner wall. I would have left the plywood in place but the splashwell limits the thickness of the transom. I have many more pics and will try to post them tomorrow. Clamping the foam on the sides was very tricky wait till you see my solution in the pics.
 

SKIBUM1M

Chief Petty Officer
Joined
Jul 17, 2009
Messages
604
Re: transom and floor replacement

IMG00019-20091122-2300.jpg

I built cross braces out of fir wrapped in fiberglass and then fiberglassed them into the stringers. I then cut mat to line the stringers with to glass the floor down with.
IMG00019-20091122-2300.jpg

Then I glassed and screwed the deck down and then tabbed in the sides
IMG00021-20091123-0031.jpg

IMG00023-20091123-0031.jpg

Next it was time to clamp the foam back on the sides. I used everything I had including spring clamps, c clamps, and a valve spring compressor. to hold the bottom I used 2 spring loaded shower curtain rods.
IMG00024-20091124-0017.jpg

IMG00025-20091124-0018.jpg
 

BobsGlasstream

Commander
Joined
Sep 11, 2009
Messages
2,128
Re: transom and floor replacement

SKIBUM1M,
That looks like a lot of work to save some foam.
Like I told you before not much with eat it. :redface:
Looks good
Bob
 

SKIBUM1M

Chief Petty Officer
Joined
Jul 17, 2009
Messages
604
Re: transom and floor replacement

I understand bob but i dont know how to do foam on a vertical surface and then the cost of the foam and the fiberglass to coat the inside. It just seemed cheaper and easier to me to reuse what was there. I do need to find a way to fill the valley between the new deck and the edges. It was filled with some sort of foam. What can I use that will fill this area that is about 1 inch deep and 2 to 6 inches wide?
 

BobsGlasstream

Commander
Joined
Sep 11, 2009
Messages
2,128
Re: transom and floor replacement

SKIBUM1M,
We all do what we feel comfortable with and your idea isn't a bad one.
As for me, I work with foam everyday so I have a inside track.
My cost is better then most too. :D
I actually built a display for a show once and had to pour vertical walls with foam. It was a mountain scene for animals. Came out pretty cool too.

For that small area you mentioned you could just use some of that pink stuff from HD, get one of those small kits of foam, or not worry about it leave it empty.
Your project is coming right along and looking good.
Bob
 

SKIBUM1M

Chief Petty Officer
Joined
Jul 17, 2009
Messages
604
Re: transom and floor replacement

Thanks Bob for understanding and not being like many in other fields who insist there is only one way to do something and putting down someone who finds a way to make a project fit their means and budget. I am a mechanic and have seen many creative repairs on cars. If i see someone doing something I know wont work I will offer advice and explain why it wont work. But I have been amazed at what some people can do to make cars last and even learned from some of them. Necessity is the mother of all invention and just because we have all done things this way for years doent mean it is always the best way or the only way.
As far as filling the valley... are you talking about using the cans of "Great stuff" That is my plan as of now because i am laying carpet over it and want it to feel right underfoot. I have almost considdered using some leftover interior house paint but i dont know if it would harden that thick. Only considdered it because it would self level nicely and I have 17 partial gallons that I need to dispose of anyway and figured if it would work it would be the most environmentally friendly way to recycle it.
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,174
Re: transom and floor replacement

I ended up using fiberglass resin to reattach the foam. the foam is in great shape and doesnt look like it has ever gotten wet since it has a fiberglass inner wall. I would have left the plywood in place but the splashwell limits the thickness of the transom. I have many more pics and will try to post them tomorrow. Clamping the foam on the sides was very tricky wait till you see my solution in the pics.

oh yeh, heheh,I had to trim the splashwell to get it back in too.:D
 

archbuilder

Vice Admiral
Joined
Sep 12, 2009
Messages
5,697
Re: transom and floor replacement

Skibum,

Great looking project, looks a lot like what I'm doing with the Nescher!
 

SKIBUM1M

Chief Petty Officer
Joined
Jul 17, 2009
Messages
604
Re: transom and floor replacement

The last of the foam is drying from being reinstalled. I just bought my 4th and hopefully last gallon of fiberglass resin. I will put another coat on the floor and prep the top edge for new screw backing strips and pl premium them in place.
 
Top