1984 Checkmate Enforcer restoration ? Part II ? The Floor
For the purpose of this post, see Part I ? Intro and Paint.
If you don?t want to read this whole post then skip to the bottom to see the What I Learned and If I Had To Do It Over Again bullet points.
Floor
I was originally just going to replace the carpet, but when I pulled it up I saw the ?" un-glassed plywood patch over the whole cockpit. So I decided to take that up. It was installed with adhesive and rusted screws (probably originally galvanized). A few of the screws broke off and I had to drill them out. A crow bar, pry bar and hammer loosened the patch. Thank goodness for all my years at the gym because it was a bear. Underneath was the original ?" (?) ply with a dry, but rotted hole over the rear of the gas tank and one near the passenger seat. No current moisture to speak of, but I did notice the floor supports were un-glassed, free-floating and had been exposed to moisture. I decided to rip everything out.
Here?s where it started to get tricky. The cockpit side panel support sprouts from the edge of the floor and the plywood runs partially under it, with some Bondo-like material between the plywood and the hull. I wanted to save these panel supports. So how do I cut close enough to the edge of them? Even if I didn?t want to save them ? how do you get close to the floor/hull joint? My circular saw would?ve left several inches. All the posts said to cut with a circular saw then angle grind to the hull. How long would that take and how much of a mess that would make to grind off three or four inches of plywood and glass? There had to be a better way. Always needing more tools, I bought a Craftsman mini circular saw. I used it for every straight cut on this project. It?s very precise. It cut within about an inch of the support. Then I stared at that remaining inch for the next month or so trying to figure out how to remove it. I was able to pry some of the wood out, but not all of it. I knew an angle grinder with a cut-off wheel would just burn the wood. I also knew that an angle grinder would still be the perfect tool if it had a circular saw blade. But did such a thing exist? It did. It?s called a C7 Bad Blade. It?s the most dangerous looking tool I?ve ever used. But it took that edge clean off in one quick pass. Well, except for a few nubs here and there. You need really steady and firm hands to keep it from cutting too deep and from kicking back. If you decide to try this combo, do not put any body part behind it. I?d hate to see the damage it could do if you were kneeling behind this thing when it kicked back. Now on to those remaining nubs.
The Bad Blade was too brutish to fine-tune the edge up to the support. So I tried my trusty Harbor Freight multi-tool ? a fabulous tool for the money. I used the flat blade that came with it and promptly wore it completely down in less than five minutes. The fiberglass was just too hard. So I stared at those nubs for another couple of weeks. I decided to stop in Harbor Freight and pick up the $7 flat blade for cutting metal. That did the trick ... a perfectly flat edge and no grinding.
Now I had the floor almost completely out. Since the last couple of feet of the rear floor outside the stringers were fine I decided to leave them. They were a pain to get to and I would have had to cut a support away from them. That was my first big mistake. What I didn?t recognize was how bulged the old floor was ? I suppose from the original foam pour. More on that later.
So now I pondered the foam removal. I decided on a butcher knife ? three for $3 at the dollar store. Between that and a pry bar it worked pretty well, but still took a whole day. The floor supports just lifted right out. There were two on each side separated with a tiny piece of plywood. All were remarkably spindly, either ?" or 3/8". It was obvious the foam was doing most of the supporting.
So now it was down to the bare hull. The core looked fine. I tapped around with a phenolic hammer. All "thwacks", no "thunks". Same with the stringers, which were heavily glassed and fortunately missed by all the screws of the cockpit patch.
I saved the old floor supports for templates and traced them onto ?" ply. I decided to make another pair for the rear. After tracing and cutting out that pair I had forgotten that the floor angle changes the further back it goes and they didn?t fit.
I eyeballed the gap under the support and next to the stringer and traced the support plus gap onto some cardboard. Once I fine-tuned the cardboard, I traced it onto the ply and tried again. I cut the corners off the floor supports at the hull/stringer joint so water could drain from compartment to compartment. Then I brushed the supports with a few coats of 50/50 antifreeze (more on that later). After they were thoroughly dry, I added a couple of coats of epoxy. Then I sanded them. Now I started reading articles on how to bed the supports to the hull. From reading stringer replacement posts I knew you weren?t supposed to epoxy stuff directly to the hull. There was a compelling post from someone about using PL Concrete and Masonry Sealant. I spread out a line and it looked perfect for the job (however, more on this later). I bedded the supports and put a clamp on the stringer on each side of the support to make sure it didn?t lean. After it set up I moved on to my first experience with fiberglass cloth.
I don?t remember the weight, but the fiberglass cloth was fairly light. Even so, this is where I learned that fiberglass cloth does not like to go over a sharp edge. I cut the cloth and laid fitted pieces over all six supports. Then I mixed up a batch of epoxy (US Composites 3/1). Once I started applying the epoxy, the cloth kept forming a dome over the top of the support. I kept stretching the sides with my hands (thank goodness for latex gloves) and dabbing more epoxy on top until it got really sticky and flattened out somewhat. Still near the edge of the hull there was a cloth bubble that I just couldn?t get rid of. I let that cure then cut it out with my multi-tool and glassed another piece of cloth over that area.
I took measurements from the middle of the stringers to the sides of the hull about every foot. Then I traced those measurements onto a piece of ?" ply. Somehow, it came out too big. Better too big than too small. A little trimming here and there did the trick. Then I measured from the inner edge of the side floor panels to get the size of the middle floor panel.
Once I had them cut and fitted, I brushed on a few coats of 50/50 antifreeze. Then I applied two coats of epoxy. One of the panels beaded up because I must not have washed off all the anime blush. I had to sand it down and do it again. I also cut, coated with antifreeze and epoxied two pieces of ?" ply that run under the side floor panels. I sanded everything and epoxied these pieces to the underside. I sealed off the joint with PL Premium. Then I glassed the whole underside with chopped strand mat. That?s when I ran into the "fiberglass cloth going over a sharp edge" thing again. More cutting out bubbles and re-glassing the corners. Then I fit them again to check the depth. The doming of the fiberglass cloth on one support made it too high and the floor was wobbling like a teeter-tooter. Instead of cutting the support down and re-glassing it, I decided to cut a slot in the bottom of the ?" piece of ply. I didn?t have a proper router bit, so I used the mini circular saw to make several 1/4" deep cuts and then I chiseled it out. Then I applied some epoxy to the slot.
Now I had to decide whether to pour the foam (US Composites, 2 lb) before or after I glued the floor down. I decided I liked the idea of the foam being form-fitted to the bottom of the floor for support. Plus, I thought form-fitting the foam would make fewer gaps for water to sit. I laid the floor pieces down and mapped out where to drill the holes for the foam pour. Then I drilled twelve 1" holes in each side panel and six ?" holes over the gas tank. I epoxied the rim of the holes.
Since the PL Concrete and Masonry Sealant worked so well to bed the supports, I figured I?d use it to glue the floor down. That?s when I learned its viscosity is a lot different at 95̊than it is at 75̊. I mixed up some thickened epoxy using wood flour and cabosil. The wood flour seemed to be much better at thickening than the cabosil. I spread that mixture where the floor joins the hull and then I shot the concrete sealant on the stringers and floor supports. It came out runny ? too late now. I set the panels down and for some reason one corner of one of the side panels didn?t fit anymore. I tried to beat it into submission, but I only got it part way down. It?s still sticking up about ?". Forget it. The epoxy?s setting up and this corner is behind the back seat.
Even though runny, the sealant seemed to adhere pretty well. Now it was time to pour the foam. I wasn?t sure my hand was steady enough to hit a ?" hole so at first I tried a funnel. That was a mistake. I just couldn?t keep the neck of the funnel clear between holes. Luckily, using drinking cups, my hand was steady enough to pour directly into the holes without making too much of a mess.
Once the foam cured, I hand chiseled the excess foam that was sticking out of the holes. Since I was about to plug the floor seams with PL Premium I decided to use that to flatten the foaming holes. You see, foam doesn?t "chisel" flat. It comes out in chunks. This is another example of not knowing what tool to use for the job. I learned something else here too. PL Premium expands. I wound up with little domes over the foaming holes. I hand-chiseled those flat. PL worked well on the floor seams though.
Now to glass the top of the floor. Good news here. No edges to go over, save the one down into the cabin. I was going to use fiberglass tape at the edges, but decided against it as I thought it would be too thick. The floor was already adhered well and the PL Premium plugged up the seams great, even that ?" that was sticking up on the back corner. So I rolled out two sheets of cloth that overlapped the cockpit side supports on the sides and each other in the middle, cut them to fit, mixed up a bucket of epoxy, poured it directly on the cloth and spread it with a GlassKoter roller and jabbed the corners with a chip brush. This was by far the easiest of all the floor tasks, and it came out great. I even kept the threads straight.
Now that the carpet is down it looks like a professional job. I'll include a picture of how well carpet hides an amateur's mistakes later.
What I Learned:
If I Had To Do It Over Again:
For the purpose of this post, see Part I ? Intro and Paint.
If you don?t want to read this whole post then skip to the bottom to see the What I Learned and If I Had To Do It Over Again bullet points.
Floor
I was originally just going to replace the carpet, but when I pulled it up I saw the ?" un-glassed plywood patch over the whole cockpit. So I decided to take that up. It was installed with adhesive and rusted screws (probably originally galvanized). A few of the screws broke off and I had to drill them out. A crow bar, pry bar and hammer loosened the patch. Thank goodness for all my years at the gym because it was a bear. Underneath was the original ?" (?) ply with a dry, but rotted hole over the rear of the gas tank and one near the passenger seat. No current moisture to speak of, but I did notice the floor supports were un-glassed, free-floating and had been exposed to moisture. I decided to rip everything out.
Here?s where it started to get tricky. The cockpit side panel support sprouts from the edge of the floor and the plywood runs partially under it, with some Bondo-like material between the plywood and the hull. I wanted to save these panel supports. So how do I cut close enough to the edge of them? Even if I didn?t want to save them ? how do you get close to the floor/hull joint? My circular saw would?ve left several inches. All the posts said to cut with a circular saw then angle grind to the hull. How long would that take and how much of a mess that would make to grind off three or four inches of plywood and glass? There had to be a better way. Always needing more tools, I bought a Craftsman mini circular saw. I used it for every straight cut on this project. It?s very precise. It cut within about an inch of the support. Then I stared at that remaining inch for the next month or so trying to figure out how to remove it. I was able to pry some of the wood out, but not all of it. I knew an angle grinder with a cut-off wheel would just burn the wood. I also knew that an angle grinder would still be the perfect tool if it had a circular saw blade. But did such a thing exist? It did. It?s called a C7 Bad Blade. It?s the most dangerous looking tool I?ve ever used. But it took that edge clean off in one quick pass. Well, except for a few nubs here and there. You need really steady and firm hands to keep it from cutting too deep and from kicking back. If you decide to try this combo, do not put any body part behind it. I?d hate to see the damage it could do if you were kneeling behind this thing when it kicked back. Now on to those remaining nubs.
The Bad Blade was too brutish to fine-tune the edge up to the support. So I tried my trusty Harbor Freight multi-tool ? a fabulous tool for the money. I used the flat blade that came with it and promptly wore it completely down in less than five minutes. The fiberglass was just too hard. So I stared at those nubs for another couple of weeks. I decided to stop in Harbor Freight and pick up the $7 flat blade for cutting metal. That did the trick ... a perfectly flat edge and no grinding.
Now I had the floor almost completely out. Since the last couple of feet of the rear floor outside the stringers were fine I decided to leave them. They were a pain to get to and I would have had to cut a support away from them. That was my first big mistake. What I didn?t recognize was how bulged the old floor was ? I suppose from the original foam pour. More on that later.
So now I pondered the foam removal. I decided on a butcher knife ? three for $3 at the dollar store. Between that and a pry bar it worked pretty well, but still took a whole day. The floor supports just lifted right out. There were two on each side separated with a tiny piece of plywood. All were remarkably spindly, either ?" or 3/8". It was obvious the foam was doing most of the supporting.
So now it was down to the bare hull. The core looked fine. I tapped around with a phenolic hammer. All "thwacks", no "thunks". Same with the stringers, which were heavily glassed and fortunately missed by all the screws of the cockpit patch.
I saved the old floor supports for templates and traced them onto ?" ply. I decided to make another pair for the rear. After tracing and cutting out that pair I had forgotten that the floor angle changes the further back it goes and they didn?t fit.
I eyeballed the gap under the support and next to the stringer and traced the support plus gap onto some cardboard. Once I fine-tuned the cardboard, I traced it onto the ply and tried again. I cut the corners off the floor supports at the hull/stringer joint so water could drain from compartment to compartment. Then I brushed the supports with a few coats of 50/50 antifreeze (more on that later). After they were thoroughly dry, I added a couple of coats of epoxy. Then I sanded them. Now I started reading articles on how to bed the supports to the hull. From reading stringer replacement posts I knew you weren?t supposed to epoxy stuff directly to the hull. There was a compelling post from someone about using PL Concrete and Masonry Sealant. I spread out a line and it looked perfect for the job (however, more on this later). I bedded the supports and put a clamp on the stringer on each side of the support to make sure it didn?t lean. After it set up I moved on to my first experience with fiberglass cloth.
I don?t remember the weight, but the fiberglass cloth was fairly light. Even so, this is where I learned that fiberglass cloth does not like to go over a sharp edge. I cut the cloth and laid fitted pieces over all six supports. Then I mixed up a batch of epoxy (US Composites 3/1). Once I started applying the epoxy, the cloth kept forming a dome over the top of the support. I kept stretching the sides with my hands (thank goodness for latex gloves) and dabbing more epoxy on top until it got really sticky and flattened out somewhat. Still near the edge of the hull there was a cloth bubble that I just couldn?t get rid of. I let that cure then cut it out with my multi-tool and glassed another piece of cloth over that area.
I took measurements from the middle of the stringers to the sides of the hull about every foot. Then I traced those measurements onto a piece of ?" ply. Somehow, it came out too big. Better too big than too small. A little trimming here and there did the trick. Then I measured from the inner edge of the side floor panels to get the size of the middle floor panel.
Once I had them cut and fitted, I brushed on a few coats of 50/50 antifreeze. Then I applied two coats of epoxy. One of the panels beaded up because I must not have washed off all the anime blush. I had to sand it down and do it again. I also cut, coated with antifreeze and epoxied two pieces of ?" ply that run under the side floor panels. I sanded everything and epoxied these pieces to the underside. I sealed off the joint with PL Premium. Then I glassed the whole underside with chopped strand mat. That?s when I ran into the "fiberglass cloth going over a sharp edge" thing again. More cutting out bubbles and re-glassing the corners. Then I fit them again to check the depth. The doming of the fiberglass cloth on one support made it too high and the floor was wobbling like a teeter-tooter. Instead of cutting the support down and re-glassing it, I decided to cut a slot in the bottom of the ?" piece of ply. I didn?t have a proper router bit, so I used the mini circular saw to make several 1/4" deep cuts and then I chiseled it out. Then I applied some epoxy to the slot.
Now I had to decide whether to pour the foam (US Composites, 2 lb) before or after I glued the floor down. I decided I liked the idea of the foam being form-fitted to the bottom of the floor for support. Plus, I thought form-fitting the foam would make fewer gaps for water to sit. I laid the floor pieces down and mapped out where to drill the holes for the foam pour. Then I drilled twelve 1" holes in each side panel and six ?" holes over the gas tank. I epoxied the rim of the holes.
Since the PL Concrete and Masonry Sealant worked so well to bed the supports, I figured I?d use it to glue the floor down. That?s when I learned its viscosity is a lot different at 95̊than it is at 75̊. I mixed up some thickened epoxy using wood flour and cabosil. The wood flour seemed to be much better at thickening than the cabosil. I spread that mixture where the floor joins the hull and then I shot the concrete sealant on the stringers and floor supports. It came out runny ? too late now. I set the panels down and for some reason one corner of one of the side panels didn?t fit anymore. I tried to beat it into submission, but I only got it part way down. It?s still sticking up about ?". Forget it. The epoxy?s setting up and this corner is behind the back seat.
Even though runny, the sealant seemed to adhere pretty well. Now it was time to pour the foam. I wasn?t sure my hand was steady enough to hit a ?" hole so at first I tried a funnel. That was a mistake. I just couldn?t keep the neck of the funnel clear between holes. Luckily, using drinking cups, my hand was steady enough to pour directly into the holes without making too much of a mess.
Once the foam cured, I hand chiseled the excess foam that was sticking out of the holes. Since I was about to plug the floor seams with PL Premium I decided to use that to flatten the foaming holes. You see, foam doesn?t "chisel" flat. It comes out in chunks. This is another example of not knowing what tool to use for the job. I learned something else here too. PL Premium expands. I wound up with little domes over the foaming holes. I hand-chiseled those flat. PL worked well on the floor seams though.
Now to glass the top of the floor. Good news here. No edges to go over, save the one down into the cabin. I was going to use fiberglass tape at the edges, but decided against it as I thought it would be too thick. The floor was already adhered well and the PL Premium plugged up the seams great, even that ?" that was sticking up on the back corner. So I rolled out two sheets of cloth that overlapped the cockpit side supports on the sides and each other in the middle, cut them to fit, mixed up a bucket of epoxy, poured it directly on the cloth and spread it with a GlassKoter roller and jabbed the corners with a chip brush. This was by far the easiest of all the floor tasks, and it came out great. I even kept the threads straight.
Now that the carpet is down it looks like a professional job. I'll include a picture of how well carpet hides an amateur's mistakes later.
What I Learned:
- You really need to thoroughly wash an epoxied piece to remove all the anime blush before applying another coat of epoxy. One of my supports and one floor piece beaded up like I had just waxed the thing. I had to sand it down again. And even with 40 grit that isn?t an easy job.
- Replacing a floor is frustrating and a ton of work if you don?t know what you?re doing. I?m sure I could replace a floor in two or three days now that I?ve been through it. But that first time ?
- Every floor probably has its own unique attributes that you won?t read about in someone else?s restore.
- Fit the floor again before you put the glue down.
- If you?re not going to cut the whole floor out make sure it butts flat against the new piece. I have a bulge where my old and new floor joins, but it?s behind the back seat.
- Fiberglass cloth doesn?t like to go over an edge.
- Know what tools to use before you start.
- A solution of 50/50 antifreeze, borax and boric acid is said to prevent rot. I wasn?t going to boil up that solution, so since an experiment with glycol alone showed rot prevention, I just decided to go with plain antifreeze.
- PL Premium expands. Spread accordingly.
If I Had To Do It Over Again:
- I?d use the right tools for the job.
- I would glue the floor with PL Premium.
- I would replace the "whole" floor.
- I?d figure out how to measure things a little more accurately. I?d probably use cardboard as a floor template.
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