first boat - 1974 Starcraft Capri 15' trihull restore/floor project started

[admjmck]

I just purchased this on Craigslist knowing it needed a floor. I have cleaned out all the leaves walnuts and acorns to see what I have to work with (the previous owner tore out most of the floor). I got the boat and trailer for $250. The hull is in great shape, interior not so much. The goal is to turn this into a fun little fishing boat, We plan to use this on a couple of local 10 hp limit lakes for fishing (with a 2 yr old and 4 yr old), nothing too extreme.

I have been browsing and reading this site for a little while and I have a few "beginner" questions:

1) is it okay to stand on the hull from the inside (I am 6'3" about 230)? or should I put planks down to walk on?

2) I have been reading about replacing the stringers with wood and fiberglassing them in, but I have also read about using seacast for stringers. I can lift the wood straight out of most of these stringers and I have more or less fiberglass forms left. Any thoughts on just using seacast?

3) There are only 3 stringers, I was expecting at least some rotten wood near the edges, should there be more supports for the floor along the sides? I haven't been able to find anything about the original layout for the supports.

4) Foam, there isn't any in the boat. Need it or not?

Here are my thoughts, but of course I haven't done any of this before. Pull all the wood, put a couple of brass or aluminum drain pipes through the stinger forms (to get water to the center/drain). Pour seacast. Put foam in along the 2 outside cavities to support the floor and provide flotation. I work in a sign shop and I am planning on using an aluminum composite for the floor.

Thanks for any suggestions!

 

[jigngrub]

Re: first boat - 1974 Starcraft Capri 15' trihull restore/floor project started

Eeewww dude! Somebody pranked you and smeared that fiberglass stuff all over your tinny Starcraft!!! J/K

1. Standing inside the hull... you may want to add additional supports under the boat on the outside as well as the trailer bunks or build a cradle for the boat that offers more support than just the trailer bunks.

2. You can Seacast the stringers, but it's a very expensive material to work with.

3. There isn't any wood along the sides because it looks like the deck was supported by the hull along the sides.

4. Foam was probably saturated and removed by the PO. You need to reinstall the foam.

Not sure what you mean by an aluminum composite floor, but the decking in a fiberglass boat needs to be wood and fiberglass. The fiberglass ties the hull and deck together to strengthen the whole boat. A deck seperate from the boat won't work and will weaken the boat overall.

 

[admjmck]

Re: first boat - 1974 Starcraft Capri 15' trihull restore/floor project started

I'll just keep grinding away at the glass until I find the aluminum then!

This is the material I was thinking of for the deck, DIBOND? 1/4" thick high density plastic sandwiched between aluminum skins. It is available in 5'x10' sheets and sometimes our distributors have scratched or damaged sheets they are looking to get rid of.

My original thought would be use the 3 stringers in the middle and put a stringer right on each side that I could screw down into to tie it all together.

Where would you add the foam? Given the stringer layout it seems to me that adding foam on either side of the main stringer would just hold water in there (unless I ran PVC pipe or something under the foam to drain the water to the back).

 

[jigngrub]

Re: first boat - 1974 Starcraft Capri 15' trihull restore/floor project started

Again, decking in a fiberglass boat needs to be plywood. Not only does the plywood decking strengthen the boat when it's tabbed to the hull, it also creates a waterproof seal around the edges of the deck and will direct the water to the back of the boat bilge area.

Most tri-hulls don't even have an active bilge that accepts water, they have a bilgewell/deck drain system. This is a small area maybe 2'x2' or smaller at the transom that is boxed out from the other below deck area, there's no decking in this area and the sides boxed in with stringers or false stringers and a bulkhead at the fore end of the well. All the water that gets on the deck drains back to this box to be pumped out by the bilge pump or let out by pulling the drain plug.

The rest of the below deck area on most tri-hulls is foamed solid with expanding urethane foam. The foam seals off the below deck area so water can't get in, the foam will also seal any breaches in the hull to prevent water entry should the hull be breached. There is no concern for drainage below deck with this design. Everything is sealed and there's no way for water to enter the below deck area.

Should I ever rebuild/restore a tri-hull, this is the design I'll use.

 

[admjmck]

Re: first boat - 1974 Starcraft Capri 15' trihull restore/floor project started

Would you put cross bracing between the stringers as well? I can't seem to find anything online about the original layout.

 

[jigngrub]

Re: first boat - 1974 Starcraft Capri 15' trihull restore/floor project started

Would you put cross bracing between the stringers as well? I can't seem to find anything online about the original layout.

Yes, I'd put "stand up" bulkheads in like the ones in this boat:

Not as many as in that boat, I'd probably "quarter up" the boat and put in 3 sets equally spaced.

This is what the deck drain/bilgewell looks like on a fiberglass tri-hull Starcraft:

Looking aft (at the transom) with the cap still on the boat:

This is looking down from outside the boat with the cap off:

[/QUOTE]

 

[admjmck]

Re: first boat - 1974 Starcraft Capri 15' trihull restore/floor project started

There seem to be as many opinions on stringer material as there are members of the forum!!!!

I am thinking 1/2" or 3/4" plywood for the stringers. Could I use 1x lumber? any cons to that? The only thing I can think of is it will be hard to find a flat straight 12' piece. I know I will have to glue up the center stringer if I use plywood.

Opinions on coating the stringers w/resin before they are installed? It seems like the resto projects on the board are pretty split. Some say yes to make sure they are water tight, some say no need because you are putting it into a bed of PB and then coating it anyway.

 

[jigngrub]

Re: first boat - 1974 Starcraft Capri 15' trihull restore/floor project started

Plywood for stringers will be your best build, I'd go with 3/4" (3/4" ply for bulkheads too).

Bed your stringers in and when you get ready to glass them in coat with resin and wait for it to tack up, then apply your cloth and wet it out.

Polyester resin has no strength by itself, so if you coat the stringers and let it cure before you apply the cloth you'll have a weak link between your layups and stringer.

 

[admjmck]

Re: first boat - 1974 Starcraft Capri 15' trihull restore/floor project started

I was able to get the rubber out of the rub rail (long flat blade screwdriver and the sun made all the difference!) and got the stainless screws out of the trim just fine. Once I got the trim off I found that some knucklehead put about 50 regular screws through both pieces of fiberglass under the trim to hold the cap on. Maybe half of them backed out, the rest of them had to be drilled out.

I was able to get the cap loose everywhere except the back near the splash well. From what I read on other threads I am guessing the transom was glued to the splash well. I climbed back and felt under the splash well and it felt like the fiberglass connected them. I ended up using an oscillating tool to cut the splash well. Hopefully it won't be too big a deal to fix later!

Any recommendations on what to use for the rim of wood inside the hull that the cap screws into? I looks like 1"x1" pieces running the length (at least the few areas it is left. resin coated plywood for this to?, or treated lumber? Glue it in place or PB it? The current pieces that I have seen so far have not had any fiberglass on them.

Hopefully getting the cradle ready and pulling the cap this week!

 

[Woodonglass]

Re: first boat - 1974 Starcraft Capri 15' trihull restore/floor project started

Glassin the Splashwell will be easy smeazy! I'd rip some Douglas Fir for the cap when the time comes and just paint it with some Rustoleum Oil paint. Predrill the holes and coat with 3M 4200 when reinstalling the RR.

 

[admjmck]

Re: first boat - 1974 Starcraft Capri 15' trihull restore/floor project started

Thanks for chiming in, I was actually just reading your post on stringers and transoms (http://forums.iboats.com/boat-resto...lly-started-w-pics-384982-25.html#post3586813) and had a few questions. You say to use CSM if the surface is rough or irregular, would plywood be considered rough? What weight of CSM do you recommend? I know for tabbing you only use narrow (6"?) strips, after it is tabbed in is it easier to work with the 38" or 50" material?

Do you have a good PB recipe? I saw one the other day and now I can't find it again. when I search for it I just get tons of threads mentioning it.

I am trying to get my materials list together and I haven't been able to find anything with quantities. Any idea on how much to start with?

Thanks for all the help!!!

 

[Woodonglass]

Re: first boat - 1974 Starcraft Capri 15' trihull restore/floor project started

This all should help...

(Click the pic to download and view the pdf File)

View attachment MaterialsList.pdf

How to make Peanut butter (thickened resin) - YouTube

Always use 1.5 oz CSM and I always get the 50"

 

[admjmck]

Re: first boat - 1974 Starcraft Capri 15' trihull restore/floor project started

It rained all morning so the boat didn't make it off the trailer today. But I got the cradle 90% finished, just have to fasten the final side supports once the boat is on it. Hopefully tomorrow afternoon or Monday night the boat will be in the garage!

Would it hurt the cap to set it on 4 or 5 sawhorses? I was thinking of putting one sort of across the bow and the others around the perimeter. I figured that is kind of how it is supported anyway.

 

[Hubble74]

Re: first boat - 1974 Starcraft Capri 15' trihull restore/floor project started

I am sorry my restore has been on pause for a few months since I have the exact same boat. I have all the material to built the cradle but have been struggling to get the 40 year old rubber out of the rub rail.