Complete rebuild of 1979 Checkmate Eluder

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I was going to start this thread in the "completed projects" section, but noticed that I can't start a thread there (so I'm guessing the moderators will move this over once I complete the thread.)

I finished this rebuild over a year ago and thought I'd create a thread detailing the entire process so that maybe someone can learn from it, especially since there seem to be quite a few older Checkmates being restored now. When I was a kid we had a cabin on Higgins Lake in Michigan and the oldest son of one of my dad's friends had a Checkmate with a 150 Merc Tower of Power. I fell in lust with that boat, I remember many mornings hearing the scream of that engine and watching Kenny disappear across the lake followed by a huge rooster tail. In my opinion nothing matches the look of vintage Checkmates, especially the closed bow models, but for me a bowrider was the only way I could get permission from the Admiral to do a Checkmate project since it's more family friendly.

I found my project Checkmate online, the seller stated that it was lake ready and only had one soft spot in the bow. Well, having already replaced the transom in my other boat I knew full well what soft spots usually mean. I was still interested because the asking price wasn't too bad even for a project boat (and I held out the slightest hope that I could simply replace a section of the deck and be done with it).

When I got the boat home I did a complete inspection and found extremely wet foam under the deck and wood so rotted around the flotation box in the stern that it would crumble with only slight help from a screwdriver. It was obvious that this boat had been left out in the weather uncovered for a long time.



Here's a photo of that "soft spot" in the bow after removing the carpet. The plywood under this section of the bow was completely gone, all that remained was a layer of fiberglass. I also found that the stringer was mush.

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And here's the side of a 'flotation box' in the stern (this side of the box also serves as a transom knee so it's an integral part of the structure). The wood was totally rotten and with just a layer of glass there was absolutely no structural integrity, it took very little poking with a screwdriver to get through the glass and remove this wood "mulch".


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Here's a photo of what I found in the bilge after removing the fuel tank. Notice that the brass insert for the drain plug hole is coming out, which probably exposed the wood in the transom to water.


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This is some of the wiring as I found it. Notice the melted and burnt look :eek: .


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parrisw

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Re: Complete rebuild of 1979 Checkmate Eluder

Really looking forward to seeing more of this, I love those boats as well.
 
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Re: Complete rebuild of 1979 Checkmate Eluder

I carefully removed the deck with my Skil saw set at an angle and the blade depth set so I wouldn't cut into the hull. The ridge that was left was ground smooth with a grinder and sanding disc. Here's a photo of the forward deck removal in progress.


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After cutting out both the main and forward decks I removed all the wet foam, which weighed in at well over 200 pounds.


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I drilled a few test holes in the transom to determine if it was rotten or wet. At first the results seemed encouraging (yes, we can trick ourselves into believing something if it's going to save us a lot of hassle) - the shavings weren't at all dark and looked good. HOWEVER, within a day or two the inside of the holes were black, one indication of very wet wood.


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I collected all the shavings in zip-loc plastic bags and took them to work where I could accurately determine their water content. (One dead giveaway was the fact that within a few hours there was condensation on the inside of the baggies.) The shavings in each baggie went in a pre-weighed metal lab 'tin', I weighed each sample, placed them in an oven for 24 hours, and weighed each after coming out of the oven. I found a water content of nearly 50%, according to what I'd read that should have only been around 10 - 15%, so that transom definitely needed to be replaced.



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When I removed the jackplate this is what the mounting bolts looked like :facepalm: :

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Re: Complete rebuild of 1979 Checkmate Eluder

Here's a couple more photos showing just how wet the foam was.


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On this model and several others, Checkmate had flotation boxes running fore-aft underneath the gunwales. I originally thought they might serve a structural purpose as did the box structures in the stern, but I learned from someone who worked at Checkmate that the vertical piece is to add stiffness and that evolved into into a box simply to allow for a place to put more flotation foam. I found the wood rotted in these, just like most everywhere else.


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When I removed these boxes I had a few questions as to why they were built like they were. There was a thin sheet of foam between the flotation foam and hull, that really had me curious as to what it's purpose was. I found out that it was there simply as a barrier between the foam and hull, without it the flotation foam would form a strong bond to the hull and could cause cosmetic defects in the hull as it cured and shrank. With that knowledge I chose to use waxed paper as the barrier when I rebuilt these.

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Re: Complete rebuild of 1979 Checkmate Eluder

I removed about a gazillion rivets from the rub rail, got it safely removed and stored, and then removed another gazillion rivets that were beneath the rub rail. Most outboard boats (this one being no exception) have a structural filler between the transom and splash well that must be removed before removing the cap. I cut out the fiberglass on top of the transom to gain access, and chipped out all filler. After that it was an easy matter to lift the cap, which hung from the rafters in my garage while I worked.

But first, I fastened a 2x4 in place to support the passenger and driver console:

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Re: Complete rebuild of 1979 Checkmate Eluder

Next it was time to tear out the old transom. I carefully cut around the outline of the front skin (with a diamond cutting blade on my grinder) and was able to pry it out intact, which I would later use as a template when building the new transom. Next the wood core was removed with a wood chisel and grinder with a sanding disc. While the wood was extremely wet it still wasn't thoroughly rotted, which made for a much more difficult removal. Here's what a transom looks like after removal.


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And here's the skin after sanding off all remnants of wood:

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Re: Complete rebuild of 1979 Checkmate Eluder

I rolled the boat outside to wash away all the dust, and to get a look at the core. Most all Checkmates have hulls with a balsa core, which is incredibly strong and light. Some boat manufactures which use a balsa cored hull have a reputation for rotted cores, but not Checkmates. Very few older Checks have core issues, and those are mostly because of improperly sealed fasteners. After washing the hull there were a lot of dark spots which I feared might be because of a rotted core. However, I was able to wash away those dark spots with alcohol, so apparently it was just some staining from the foam. I didn't even have any rot in the core where the previous owner put screws all the way through the hull mounting a Hot Foot.


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Re: Complete rebuild of 1979 Checkmate Eluder

I built the new transom from two layers of 3/4 inch AB marine plywood, using the front skin from the old transom as a template. The two pieces of the transom are held together with PL Premium adhesive (applied with a notched trowel), and heavily weighted while that was curing. I planned ahead for every transom penetration and drilled oversized holes, which I then filled with a slurry of epoxy and milled fibers. Then, when I drill holes or put screws in the transom there will be no chance of water ever coming in contact with wood.


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To install the transom I painted both the wood and fiberglass skin with epoxy, then mixed up a slurry of epoxy and cabosil and applied it with a notched trowel. For a clamping system I ran threaded rod through the transom in 4 places (where there'll be holes cut anyway) and held the 2x4's down with plates cut from scrap 3/4" plywood. Not as elegant as the nice BIG clamps that others have fabricated, but they'll do. (And I even remembered to put grease on the threaded rod, I don't need those to become a permanent part of my transom).

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My Eluder has a new transom !!!!!!!!
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A few epoxy dribbles on the forward face are harmless, it'll get sanded and coated with epoxy before being glassed anyway. You can see the area that had to be routed out for the splashwell to fit, in that area the wood is only 1" thick (I checked and double checked that dimension on the original transom before removing it). Before permanently installing the new transom I put the cap back on the hull to check the fit and even after removing that 1/2" of material it was TIGHT right at the bottom of the splashwell. I ground out just a bit more wood right in that area to be sure that 2 layers of biax will fit. Notice also on top of the transom I added some filler (micro, cabosil, and epoxy) to make that surface slopes forward slightly so that water will never collect there. I also made fillets on all the edges so the glass cloth will more easily conform.


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After sanding and cleaning the transom and the hull to about 6 inches forward of the transom, I laid up 2 plies of 17 oz biax, wrapping around about 4 inches onto the hull. After the layups were completed (and before the epoxy cured) I put polyester peel ply everywhere I would be bonding to the transom for the horizontal brace, knees, stringers, etc. When I get ready to do those layups I'll just need to pull off the peel ply (which 'micro-fractures' the surface) and it's ready to go.


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Re: Complete rebuild of 1979 Checkmate Eluder

One small area of fiberglass about 10 inches long lifted up from around the top edge of the transom while the layup was curing. To fix that I drilled several small holes through the glass, about 3 or 4 inches apart. Then I mixed up a thin slurry of epoxy and milled fibers and shot it into each hole with a syringe. You can see in this photo that the delaminated area is almost completely filled now. This is a much faster method of repair (took all of about 3 minutes) than grinding off delaminated glass and laying up new, and is structurally just as sound.

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And I fabricated the horizontal brace from 2 layers of 3/4" marine plywood. It doesn't show real well in this photo, there's a bevel cut on the side that will go against the transom - I'm going to have the brace angled downward slightly, again so that water can't sit on top of it if somehow some gets splashed onto this area (no more water poisoning for this boat!)

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And here are a couple of photos showing the horizontal brace and knees glassed in (this transom is going to be STRONG). You can see on the bottom of the horizontal brace where a small amount of material had to be removed to allow installation of the jack plate mounting bolts - I was actually smart enough to check that ahead of time :D .

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Re: Complete rebuild of 1979 Checkmate Eluder

This boat originally didn't have a ski locker, I changed the configuration slightly to be able to add one. It involved moving the transition from the main deck to forward deck about 6 inches, and adding two small stringers. I fabricated these from some good quality 1X lumber, they're only purpose in life is to support the deck around the ski locker. (Originally there was only a single stringer along the centerline from about the drivers seat forward.

I'm being anal about making sure this boat never sees one bit of rotted wood again. The stringers (deck supports if ya' wanna' get technical) and bulkheads were glassed with 7725 cloth before being installed. I added blocking where the two pieces of deck will be joined (I decided it would be much easier to build the main deck in two pieces). This blocking will be under the middle of the seat boxes, not a bad place to have a bit of extra strength

It's worth mentioning that for installing stringers and the deck I temporarily re-installed the cap (but no rivets yet), this is to help ensure that the hull stays straight. If for some reason the hull twisted a bit on the trailer (perfectly possible with over 200 pounds crawling around in it) as the deck was being installed that twist would become permanent. The cap will stay on until the deck and gunwale foam-boxes are all glassed in.


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Re: Complete rebuild of 1979 Checkmate Eluder

If you haven't already post this on the Checkmate forum. www.checkmate-boats.com The folks over there love restorations with pictures.

I posted this over there as I was doing it. That's where I found some of the Check specific information which helped me so much with this rebuild (especially the information about the flotation boxes). I just figured that it was about time I posted it here on iboats as well.
 
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Re: Complete rebuild of 1979 Checkmate Eluder

I installed an inside the hull transducer, and with the limited space available in the bilge it had to go in before the deck was installed. I cut away the inside fiberglass skin to expose the core, then I had to grind through the balsa core to get to the outside skin where the transducer will be epoxied in place. Having never seen the inside of the core before, and realizing what my neighbors would think of my actions if I happend to see garage floor through the hull, I CAREFULLY cut out the balsa with my dremel and a wood chisel, proceeding VERY SLOWLY (took me about 3 hours total - this balsa's A LOT tougher than what I used to build model rockets with). The transducer mounted about a foot in front of the transom in the middle of the pad.

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I took measurements for cutting my main deck and transferred them to 1/2 inch plywood. The plywood was painted on the bottom with 2 coats of epoxy, with peel ply where it will meet the stringers. Then both sections of the main deck were mounted using a slurry of milled fibers, cabosil, and epoxy along the tops of the stringers and sides. I made a fillet along the sides with my slurry, then used everything I could find that was heavy to hold it in place for curing. Once again I had temporarily placed the cap on the hull to ensure that it wasn't twisted while this was going on.


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Then I cut the forward deck out of 1/2 inch plywood, it took a couple rounds of fitting to get it perfect. The boat originally had a build in cooler in the forward deck, I didn't want that and decided to install a hatch cover there instead. There won't be any stringers under this section of deck so to add stiffness I cut out some ribs from scraps of 3/4 marine plywood, they'll be doing double duty as a base for the hatch cover. These ribs will get two plies of 1708, and the entire underside will get a ply of 7725 cloth (cut at a 45 degree angle so it will lay down better over the ribs). That, along with a layer of 7725 cloth on the topside will make it plenty strong.


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Here's a photo after the forward deck was installed. I'd cut approx. 2 inch diameter holes in the aft deck (outboard of the ski locker - notice that I haven't cut out the ski locker yet) to for pouring in flotation foam. This photo was taken after the installation of foam.

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tpenfield

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Re: Complete rebuild of 1979 Checkmate Eluder

Nice project. I admired Checkmate's when I was young. Good to see one is being brought back to life.
 
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Re: Complete rebuild of 1979 Checkmate Eluder

Here is a photo of the test fitting of the flotation boxes and battery trays. One thing I saw during the demolition phase was that some water had gotten into the flotation boxes from above (there wasn't a top on them), possibly from where the steering cables pass through the splashwell. I'm adding a piece of 1/8 plywood to go over the flotation box, and sloping it downward so any water will run off. This of course will be painted with epoxy on the inside and fiberglassed on the outside to make sure that it's waterproof.

A bit of 20:20 hindsight - with the cap off the boat and no rear seats or fuel tank in the way this location for battery trays looks perfect. HOWEVER, now that the boat is back together I've discovered that it's a b*%#% to reach the battery trays, I wish I'd have left them much further forward.


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I've often heard that bondo has no place in a boat, and that's mostly true. However, it's slicker than snot on a doorknob for temporarily holding pieces in place - mix it with a little extra hardener to speed curing time and it will cure extra brittle to make it a snap to remove with a wood chisel or screwdriver. A couple blobs of bondo are visible in this photo where I'm working on fitting a battery tray.


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After test fitting everything I glassed all the plywood parts for the flotation boxes and battery trays. Instead of doing them one at a time I took a shotgun approach to save time. I put a layer of wax paper on a large piece of plywood, put a sheet of peel ply on that, then the first layer of glass cloth. I arranged the parts on the glass cloth as tightly together as possible, and marked their outlines with a felt marker. Then one at a time I painted epoxy on the bottom of each part, wet out the corresponding area of the glass cloth, pressed the part onto the wet-out cloth, and then painted the edges of each part with epoxy. Then the tops of all the parts were painted with epoxy, the top layer of glass cloth laid over them, and enough extra epoxy painted on to ensure good wet-out. Finally a sheet of peel-ply was put over the top ply of glass. Since the temperature was only around 60 I chose fast epoxy and used a hair dryer to help speed wet-out.

Once they cure, these parts will be tabbed in place using 7725 cloth. By using peel ply they'll be ready to install with no additional sanding.

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Here's a photo of the battery tray and flotation boxes installed. The gunwale flotation boxes are ready for foam, and the rear ones are waiting for the lids to be tabbed in, then they'll be filled with foam and finally glassed.

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Here the flotation boxes are complete, I had pre-glassed the tops and finished up by tabbing them in place using 7 oz glass tapes about 3 inches wide. The shop lights are keeping the epoxy warm enough to cure, and my circular saw was the closest thing to me when I needed some weight to hold down a corner.


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The Enforcer

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Re: Complete rebuild of 1979 Checkmate Eluder

I posted this over there as I was doing it. That's where I found some of the Check specific information which helped me so much with this rebuild (especially the information about the flotation boxes). I just figured that it was about time I posted it here on iboats as well.

I thought the restoration looked familiar, great project!!! You're Groundloop from CM website. I'm cmpulse170 from over there.LOL!!!
 
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Re: Complete rebuild of 1979 Checkmate Eluder

I traced cut lines for my ski-locker, said a quick prayer, and went at it with my jig saw. I must have done something right 'cause everything came out perfect, I'd wanted a half inch between the ski locker and stringers and that's what I got. I glassed the deck with one ply of 7725 cloth, and fabricated and installed seat boxes.

More 20:20 hindsight - I went with seat boxes because that's the way the boat was originally. If I'd have had half a brain I would have glassed a second layer of plywood to the deck where the seats are and bolted pedestals in place. It was a total pain in the a#$ getting my hands inside the seat boxes to got the seat frames bolted in place. It also would have reduced the complexity of installing carpet.


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I found a ski locker frame and cover on ebay for $20, all I used was the frame. I made a custom ski locker cover on the water jet at work.

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As I'd mentioned earlier, in an act of pure genius the previous owner screwed a Hot Foot to the hull and went all the way through the balsa core and outside skin.
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Luckily there was no water intrusion into the core. To repair those I used my dremel with a router bit and cut about 1" diameter holes through the core down to the outer skin, being certain that the exposed outer skin is clean and sanded so that epoxy will have the best possible bond to it. I also ground out a shallow valley around the screw holes.

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I put duct tape on the bottom of the hull over the holes, (don't need epoxy dribbling down the side of the hull). The inside of the routed out area was coated liberally with epoxy and the screw holes filled with an epoxy/milled fiber slurry to nearly the top of the core. After that cured the holes was filled to the top with a thick micro-baloon - epoxy slurry and two plies of glass layed up over the entire area.


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Re: Complete rebuild of 1979 Checkmate Eluder

This boat originally had plastic covers for the dash on both sides. Well, after more than 30 years that plastic was cracked and dull looking.

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I removed the plastic from both sides and was surprised at what I found under it on the driver's side.

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I talked to Mike at the factory and he told me what I expected to hear, those plastic inserts haven't been available for years. I toyed with the idea of building a flat face for the dash, but finally decided I could make an interesting looking dash out of what was already there. Soooo.. I filled all the openings with plywood, glassed over the wood, and filled and sanded (and filled and sanded and filled and sanded).

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Then applied primer and finally painted them white.


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Here's what it looks like with new gauges, new dual rack NFB steering, and a new steering wheel.



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Re: Complete rebuild of 1979 Checkmate Eluder

Instead of attempting to figure out the existing wiring mess I decided it would be much easier (and safer) to start over from scratch. I spent quite a few years designing industrial control panels so this wasn't a big deal for me. I started out with a list of all things electrical which I'd install, then drew a wiring diagram including engine connections. One of the changes I made was to install flexible conduit from the front to rear on each side (I wound up with 2 pieces on the driver's side), and another piece across the rear, to make wiring easier and to facilitate changes in the future. I did the bulk of the wiring with the cap still hanging from the garage rafters since it was way easier to access everything.

Here's a photo of the conduit along the starboard side under the gunwale, along with the alarm buzzer, shifter, and safety kill switch.

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And here's the piece across the rear, along with the fuel filter/separator:

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Here's a photo of under the dash when the wiring is nearly complete. I brought power forward, went through a master switch, then to the fuse block. All ground wires go to a common ground buss. I had several thousand feet of aircraft wire laying around and decided to use that (it's very high quality wire - you can hold it in the flame from a lighter and it's not damaged at all). The only downside of doing this is that I'm not using standard colors, but each and every wire is numbered at both ends and numbered on my wiring diagram.



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