18' Thompson Calae transom, stringers and deck

[F14CRAZY]

I'm back again...

In 2008-2009 I did the thread at the bottom of this one. Not really knowing anything about boats or glassing, I took on the 19' Bayliner Capri 1952 I had just bought. And its held up great after almost 9 years. I'll link to the old thread I had here but this forum helped me out A LOT and proves that DIY fiberglassing jobs hold up just fine. I uploaded a couple pix from when I did the restore and at our Mackinac Island wedding in 2015.

Anyway...

My father in law has an 18' Thompson Calae bowrider. 4.3L OMC Cobra. It's not bad-bad like my Bayliner was (that had open holes in the deck lol) but it's definitely rotting. I'm ordering material from US Composites once again.

I'll be using 18 oz roving for structural stuff and will be using their 3-1 epoxy.

He'd like the deck to be gelcoated (which I honestly haven't really used before). For that I am ordering 1.5 oz chopped strand mat and 3 gallons of their poly resin. I haven't really used poly resin either and just used epoxy on my Bayliner.

Is it acceptable, and does it make sense, to refrain from using epoxy on the topside of the deck, use the poly resin to put the CSM down, then a layer of the 18 oz roving, then gelcoat (pure white) with non skid compound added? I intend on applying the gelcoat with a brush or roller. I know that poly resin and gelcoat won't bond properly to epoxy so I'll be sure not to use epoxy on the topside.

When using poly resin with roving, you have to first put down CSM onto the wood before the roving, right?

I know that you have to use a wax/sanding aid before applying something like paint, but is it ok to skip using that and apply the gelcoat before the poly cures?

For the topside of the deck I've ordered 3 gallons of poly resin, 2 gallons of gelcoat and 1 quart of US Composite's non skid compound. Do those quantities roughly make sense for an 18' bowrider?

Thanks guys. I will keep posting updates as this project goes along.

 

[proshadetree]

Of all the folks F14! Man you helped me loads on my Bayliner. I would tear into the boat before I ordered anything. US Composite is very fast shipping. You might need stringers or transom work. Poly is kind of date sensitive, especially the wax. Why not just go poly all the way? It is what the boat is made from and will hold up great. How did the Cris Craft turn out?

 

[F14CRAZY]

Of all the folks F14! Man you helped me loads on my Bayliner. I would tear into the boat before I ordered anything. US Composite is very fast shipping. You might need stringers or transom work. Poly is kind of date sensitive, especially the wax. Why not just go poly all the way? It is what the boat is made from and will hold up great. How did the Cris Craft turn out?

Wow, even without going back through my old thread I remember you proshadetree!

And yeah, I thought things over again and I'm going to wait till I get to the boat (probably Saturday or Sunday) and at least poke around a bit as in drill some core samples. I may wait till I really tear into it, which will probably be Monday, before placing the order.

US Composites called me back and I talked the project over with Steve there. I've adjusted my order to include 20 yards of 3/4 oz CSM to layer with the 18 oz roving I ordered from ebay already (42 yards for $49, free shipping). I guess I was ordering too much 435 poly resin and that's adjusted to 5 gallons. Epoxy was adjusted to 2 gallons which will mostly be used for bedding the stringers and laminating the plywood in the transom.

After my chat with Steve, my plan for the deck is to put a layer of CSM down, then roving, let it cure (with wax), then sand and prep to get filled with resin with cabosil, sand it, then roll on gelcoat with the non skid additive (thinned to level out better).

I think it'll work. This is pretty much my first time using polyester resin as my Capri was all epoxy. I'm looking forward to seeing how the gelcoated deck turns out though.

 

[F14CRAZY]

Here's this for posterity. I still have all the photos on my backup drive and Google Photos but the thread originally had photos hosted on my AOL FTP account, which itself is long gone.

 

[Woodonglass]

Uhmmm, there's actually no need to use two resins. Poly will do ALL the work just fine. I'd recommend using 1708 biaxial cloth. It will work for everything. You might want some 1.5oz CSM for the bottom and top of the deck. 1708 will work just fine for the stringers and the deck. Thickened Poly resin with cabosil will be all you need to bed your stringers and attach the transom to the outer skin of the boat. You might find the second link in my signature very informative. Vendors have a tendency to lead you in the way that enhances their bottom line. People here on the forum will guide you from Knowledge gained from experience.

 

[ondarvr]

I'm with Wood, you have an odd mix of products. There are much easier ways to get the same results.

 

[F14CRAZY]

Well, from what you guys have posted (I did read through woodonglass's post...thanks for that) and thinking about it, I think I'm going to change the order and swap out the epoxy for more poly resin.

With my refresher reading it seemed like poly resin was not suitable as a glue or for bedding but it seems that isn't the case. I got thinking that I should stick with epoxy for laminating the layers of plywood together for the transom and for bedding the stringers and making the fillets throughout. I'll stick with poly resin though.

 

[ondarvr]

Don't follow their recommendations on how to create the nonskid, it's not a good or easy way to do it.

 

[proshadetree]

I like the texture from just a large nap roller for gelcoat. All we used on the houseboat and its been fine. We used 5 galons of getting l. I mixed and the wife rolled. Done all the lower in one day. Has excellent nonskid and is easy on bare feet. A lot of people were against the use of poly sevral years ago. The tide has changed a bit.

 

[F14CRAZY]

Thanks for the suggestions so far. Started tearing into the boat today and yuuuuup, it's all rotten, or at least moist.

A 4x6 spanning over 4 rafters held up the 4.3L fine. I mixed this boat up with my father in law's previous boat and this is an Alpha One, not a Cobra

Core sample hole and these engine mounts weren't encapsulated...I don't believe in that and they will be encapsulated when I replace them.

Bulkhead forward of the engine. Core sample indicated pretty wet wood. And check out that delam.

These don't look bad...

NOPE

 

[F14CRAZY]

Note the block of ice in the ski locker

The frames for the bow seats and the supports for the consoles were not glassed in at all. I tried to remove them without cutting them up that much.

Plenty of soft spots and holes I was able to punch through with my boot. I'll be cutting out the deck and starting to grind glass tomorrow (Tyvek suit, chemical/particle respirator and goggles are ready).

 

[ezmobee]

Glad it's a mercruiser. More worthy of a restoration. What's the outside of this beast look like? Good luck with all the tear out.

 

[F14CRAZY]

Sorry I don't have a good exterior shot of the boat. My father in law doesn't really have any good photos of it either lol.

No lack of wet foam. The stringers are tabbed in but have no encapsulation...that's a new one for me. At least Bayliner tried with my Capri

I'm taking a break for a day but will be back at it soon. Next I have to pull the gas tank, measure everything, then start cutting out those rotten stringers

 

[F14CRAZY]

Day 3: got the gas tank, stringers and transom out

Gotta love seeing water trickling out of the transom when you cut into it

The transom came off pretty cleanly. I'm going to try to chisel the skin off a bit more cleanly before taking a flapwheel to it

And the mess from the transom. And some foam that was around the fuel tank hoses (which are being replaced...ordered them tonight)

Tomorrow I plan on grinding the remains of the tabbing down and getting the transom clean. Should be able to pick up some wood tomorrow and start cutting

Menards has marine plywood in stock actually

 

[Baylinerchuck]

Wow, you're moving quick. Nice work thus far.

 

[ezmobee]

Indeed. You don't waste any time!

 

[Woodonglass]

What resin are you using? Temps are critical for using either one. Really nice work so far!!

 

[F14CRAZY]

What resin are you using? Temps are critical for using either one. Really nice work so far!!

I have US Composite's 435 polyester resin. The shop I'm working in has a good furnace so it can be any temperature it needs to be. Is 60 degrees enough or do you think it needs to be higher?

Goodies from US Composites, along with a new battery tray my FIL ordered from Amazon.

Roseburg 3/4 marine plywood at Menard's. $3 off. Would have been nice if they had one of their 11% rebate deals going on.

My best man Brian came out and helped with cutting the transom. Main layer is 3/4, 2nd is 3/4 and 3rd is half. Similar to what I pulled out and with the out skin and the glass I add that fits within Mercury's allowable transom thickness.

Brian got a photo of me working on measuring the heights for the stringers. Like I did with my Bayliner, I measured down with a straight edge on the chine every 6 inches to roughly figure out how cut the stringers. We measured and marked every 6 inches with a permanent marker...I'm surprised it isn't visible in the photo. The deck of this boat was 4 3/4'' above the chine, unlike my Capri which had the deck sitting on the chine, so I straight edge was cut with this in mind and I just had to measure down, from the top of the straight edge. Is there any other way to figure out how to cut new stringers? This worked for me before, though I'm not sure where I got the idea from.

In the mean time, while cleaning on the gas tank, I tipped it from the end I haven't tipped it from yet and found a few pinholes. They look like they ate from the outside-in. The dimensions are fortunately pretty flexible and we're looking online for a new tank. I'm finding that I may have to re-engineer the engine compartment and cover to accommodate the filler neck being in a different spot.

So that was Day 5. Day 4 was just grinding the remains of the old glass down and getting the hull smooth. I bought a new flapwheel for that part but the old one in my angle grinder held up fine.

I suggested to my father in law to let me take on this job because of a change in my career goals...I was a student teacher but decided it wasn't for me. I can always go back to my manufacturing day job but they've been slow lately anyway. Since I'm not exactly in college at the moment and not really employed I'm able to take this on more or less full-time.

My FIL has also ordered new Wise jumpseats for the rear and matching high back seats, with adjustable pedestals (instead of the back to back seats as it originally had), Kenwood marine head unit with Bluetooth and 4 speakers, horn, a garboard drain (instead of the copper pipe and rubber plug). Thank goodness for Amazon Prime. One of the lower bolts that goes through the transom broke (the lower one with the anode) so I ordered a couple from ebay.

Today's a break day but I'll be back with it Monday.

 

[Baylinerchuck]

Looks like the transom goes to the hull. I would shorten that up a little to ensure no water in the bilge can touch the level of the wood.

Looks great, nice progress.

 

[Woodonglass]

65 to 70 is Ideal!!!