Stringer/Transom area question

hermco · #1 07-27-2007, 01:36 PM

Take a straight 2x4 x whatever you need for length and apply masking tape to edge so glass wont stick. Set in place where you cut off the lip and glass up to it from the stringer. Be sure to grind the stringers first. When it cures trim to a width of 1" and you are good to go.

JohnB · #2 07-29-2007, 09:22 AM

Thanks for the info. I was planning on tying the liner and stringers together. The liner has "sagged" down some, and has caused stress cracks in several places. I was thinking of putting some cross bracing in front and behind the tank running between the stringers. Have you ever seen/done that?

I spent a couple hours on the gas tank yesterday, and it is wedged in there pretty tight. The foam is compressed tight. I am going to put some long 2x4s underneath it, with threaded rod going through a cross brace and use the threaded rod to apply preasure. I think steady presure on it will release it out. Once I get it moving out, I will cut what I have to to remove it.

hermco · #3 07-29-2007, 09:52 AM

Quote:

I think steady presure on it will release it out.

Good luck!

BigLew · #4 07-29-2007, 09:18 PM

Just a suggestion.

Get a hand cross cut saw and cut the foam. You could do two cuts per tank side and then dig out the center section, thus giving yourself some working room. Make sure the tank is drained as much as possible, remove the sending unit, thus leaving a sizable opening into the tank. To be really safe, shoot a CO2 fire extinguisher into the opening forcing out an normal air with oxygen in it and fashion a piece of pipe with duct tape wrapped on the ends to prevent any metal to metal sparks. Attach the pipe to a "come along" or other lifting/ pulling setup and pull the tank clear slowly. This was described elsewhere on this site, so do a search. It loooked doable and reasonable to me if one were to think it through.

For the re-install, look up David Pascoe's article on how to install an aluminum fuel tank.

http://www.yachtsurvey.com/fueltank.htm

JMHO! Good luck!!!!! (and be careful- gas fumes are highly explosive!!!)

ocuyler · #5 07-29-2007, 10:35 PM

I can't resist - CHAINSAW?

JohnB · #6 07-30-2007, 09:20 PM

I have a carbide tip chain saw we use for disaster relief. It cuts wood, fiberglass, and aluminium like butter. I think I will leave it on the shelf for this one.

I tried a new approach, and the tank is freee and pretty well out, got rained on, and needed a second set of hands to catch it this afternoon. I should have it out in the AM.
I used a 6' piece of 4x4, a 3' piec of 5/8"s threaded rod, and a 5' 2x4 and it took about 2 hours to get it out.

I drilled a hole in the end of the 2x4 and slide it under the tank lengthwise. I drilled another hole in the center of the 4x4, and placed on top of the stringers just past the end of the gas tank. I slide the threaded rod through the 4x4, and down through the 2x4 that was under the gas tank. Then I put a big washer and a nut on the bottom end, underneath the 2x4. I put another washer and nut on top of the threaded rod, on top of the 4x4. Put the wrench on it, and in about 15 minutes, I had it popped free, and started sliding it toward the back of the boat. The steady presure broke it loose from the foam. I currently have the rear of the tank resting against the transom, and I will have to grind a little off the tabs to get it out.

No comes the 900 dollar question, do I replace the gas tank? It wasn't leaking. I will clean it off tomorrow, and see how bad it is.

JohnB · #7 08-01-2007, 10:39 PM

The SeaCraft soap opera continues.

The tank is out, and it looks like she is getting a new one.

Would you say this was pitted?

Now for some more fun. I suspected that a stringer was loose. I didn't suspect it was loose 1/2 the length of the boat. It seems that the port side is always the screwed up side on a seacraft. They didn't put enough glass to hold it and they didn't rough it up when they put it in there. It just pulled apart, with shiny glass underneath. The other side looks fine, and has more glass over there. I am probably going to re-enforce it. Good news is the stringers are dry and appear to be fine.

Here are some shots of the empty spaces.

One of these shows the "tool" in action. One guy, 4 hours, and the tank is out. No trying to get the foam out, it lifted straight out, even though it was twisted/shifted in there. Here is the tool I came up with.

Well, I am going to take 5 days off, and heal, regroup. That new tank is going to leave a dent in the wallet, but I don't want to do this twice.

JohnB · #8 08-16-2007, 09:47 AM

I am pretty much ready to start building. I ran into 2 things I am pondering,

1. The stringers are minimally attached to the hull on the inside. I suspect they may a little wet. I am going to hit it with a moisture meter this AM. I also have some concern that the glass isn't stuck to the stringers in some areas. There are areas near the floor I can push in with my thumb. Is this just because the stringers where square, and don't sit flush to the floor? or am I looking at something else. I am definitly going to beef up, and reattach the glass on the sides of the stringer back to the hull. The question is should I just cut the glass off the side of the stringer, and put new glass in on the side of the stringer where I can push it in, or just build up with glass over the existing? There are places on this string where it is attached that it is so thin, there are holes where the glass wasn't wetted out.

2. I have read so much on composites, glass, and epoxy, my head it going to explode. I am probably going to spend a little more money, and use Vinylester, vs poly or epoxy. The current option is going with 30 pound nylaboard which is 260 a sheet (OUCH), times 2 sheets, or go back to marine plywood. I have found that there are a lot of problems with separation between the glass and the composite board, especually if you don't have a vacuum system to pull it together. There are many production boats that are having these problems. My plan was to lay the composite coring down flat, and put a layer slow curing glass on top of it, and let it sit overnight. Then put a couple of layers of glass on the transom skin. Then put one layer between the transom skin, and the glass composite board. This would alow for max connection between the composite and the transom skin.

My question is this adds over 350 bucks to the project, and a plywood transom, especially one without a cutout will last 20-30 years. I don't know what the life of the hull is, but that would make the boat 40-50 years old. That is asking alot of of a hull. Really, the only major advantage is a little weight reduction, probably 100 pounds.

I know this has been tossed around quite a bit on here, but what does everyone think the weight difference would be? and has anyone had experience with Vinylester resin on a composite bonding/debonding?

strick · #9 08-16-2007, 10:52 AM

On the stringers I would grind out questionable areas with the grinder and then re glass to beef en it up. Myself I don't think there is anything wrong with using plywood as long as you do it right. I've used both epoxy and vinyl ester over foam coring material without any problems. Don't worry about debonding your plan sounds OK but you will need to thru bolt the transom core with something on either side of the transom say 2x4's to suck the new transom coring to the outer skin. If you use plenty of resin you should have no debonding issues. One thing to keep in mind is that some of your transom coring materials are so dense that they are nearly as heavy as plywood so the weight difference would be negligible. I would do all your repairs in epoxy and for making parts use your vinylesters and polyesters. I used vinylester on the majority of my 20 restore because it was a little cheaper then epoxy and I wanted to see what working with it was like. The fumes are a real PIA but otherwise I'm happy with with it and it appears to be plenty strong.

strick

JohnB · #10 08-17-2007, 11:00 PM

Thanks Strick,
I am leaning back toward marine plywood pretreated with epoxy, and puting it back together with vinylester resin.
If done poorly, like mine was, with unsealed holes for years, it almost made it 20 years. I don't know what the life of a hull is, but if it makes it to 40 with plywood, I won't complain. At 270 a 4x8 sheet, times 3 sheets, it really is piling up.