1964 Starcraft Bahama Restore

[hoffmanuno]

I have 1964 StarCraft fiberglass boat. I ripped up the original weakend floor and him trying to restore it. When I carefully pulled up the floor in two large sections I cut out I found what looked to be baffle shaped fiberglass stringers every 6 inches. They appear to be completely hollow, preformed in sections, and then glassed into the bottom of the boat. My plan is to clean them up and then strengthen up the weekend areas with another coat or two of fiberglass matting and then put down half marine grade plywood coated in epoxy for the floor replacement. Here's a picture of the stringers. Are they really hollow?

 

[hoffmanuno]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

Here is the pic of the boat stringers.

 

[jbcurt00]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

Pix are set to private, or the link isn't correct. But yes, they may in fact be hollow. Mine are in a 1960 Glastron FireFlite.

For beefing up the stringers you'll probably want to run a layer or 2 of CSM, or 1 later of CSM & then a layer of 1708. CSM is not compatible w/ epoxy. It's designed to work with the styrene in polyester resin. Epoxy doesn't have the styrene, so it won't break down the CSM binders. Check with whoever you get epoxy & mat from that they are compatible.

Be sure to check the transom very thoroughly for evidence of water intrusion & or rot. Now while you have the boat torn apart is much better then a year (+/-) from now. You can drill some holes into it from the inside (seal them up when your done if they show no evidence of rot. Take a 1/4" drill bit & wrap it w/ tape @ 3/4-1" from the tip. Drill some 3/4-1" deep holes into the transom as low as you can (near where the deck intersected the transom), near the drain tube. Dry & light colored wood shavings indicate a solid, undamaged transom. Wet & dark colored shavings indicate a water compromised transom that should be redone.

When you prep the ply for the deck (floor) coat the down side too. W/ CSM & polyester resin, or just epoxy (on the underside) and then lay the deck & topcoat it. Epoxy isn't UV stable, so any exposed epoxy will need to be painted.

Depending on where you're using epoxy & how you plan to finish those areas, polyester resin does not stick to epoxy very well. Epoxy will bind to polyester resin (what your boat is probably constructed w/). Epoxy tends to be more expensive per unit then poly resin, but in some applications you can eliminate some of the fiberglass (IE: the underside of the deck).

Welcome to dry dock. The crew @here will get you back in the water quick.

Lookup WoodOnGlass's posts. His signature life has some helpful links in it.

Don's helpful tips is a great resource. Friscoboater & oops should both have threads posted in that list. Really great threads.

 

[hoffmanuno]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

You were right. I had the picture set as private. I just made it public, so you should be able to see it now. Since the boat's design for the floor is similar to cardboard, I thought I would strengthen up the existing joints and any imperfections with standard fiberglass resin and woven matting (1708) after I get it all cleaned up good. If you can see the picture now you'll see that the stringers are in excellent shape. The only damage to them was from me when I drilled into them from the top of the deck to glue in bolts to hold the seats down. I can easily walk on them while tearing the deck off and they don't deform or crack one bit, so one or two layers of 1708 in a few spots should fix any damage there.

The transom is rotted, probably completely. My buddy had put two 1/4 inch pieces of aluminum plating on either side to beef up the transom years ago, but now that I'm redoing the deck I am going to rip out what's left of the transom and replace it. I'm really set on using a poured epoxy product to replace the transom in order to ensure that the rot never comes back and the fact that it will be much easier than installing another wood transom.

I will be ordering two pieces of 4x8ft marine grade plywood to replace the deck. I only need to replace a 10x4ft section, but I don't think they'll sell me a 4x4ft piece so I'll bite the bullet on that if I have to. I'm thinking of using one sheet of the 4x8 from the back up and then using the smaller piece to fill in the 2ft void in the front of the deck just in front of the seat. I figure that's the best place for a small piece to be located since there will be little to no pressure on it anyway. I will use some sort of Epoxy coating, thinking West System, to coat the marine plywood before I install it as well. I plan on using construction adhesive on the top of the many hollow stringers to hold down the flooring and then use weights to hold it in place. Once the adhesive is dry I will bond the edges of the floor to the interior of the boat/seams with strips of fiberglass and resin or epoxy, depending on what I hear will bond best. I'm going to predrill in the the holes for the seat mounts and then hammer in metal threaded inserts onto the back of the deck before I coat and install it in order to make seat removal quick and easy for repairs, maintenance, and maybe take them out for winter storage.

How does my plan sound so far? I'm also thinking of putting floatation foam in the floor's baffles in order to strengthen it up a bit and ensure that if the boat is ever swamped it will likely still float and not sink like a stone. Any thoughts?

 

[Woodonglass]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

You don't need Marine grade. Ext. Grade will do. Once encapsulated in the resin and glass it will last for decades, IF you maintain it properly. No need for epoxy either. Poly resin will be just fine. Your boat is Made from it. Why do you think the composite transom will be easier to install? It is about 300% more expensive and a Properly Fabricated and maintained wood transom will last 40+ yrs. Mine is 51 yrs old and still going strong. Besides, do you really plan on owning this boat for 40 years? No need for the added expense, IMHO

 

[jbcurt00]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

A few threads detail using an additional tapered square pc of ply mounted after the deck is tabbed & glassed into place. This above deck piece of ply could be considered sacrificial. If water ever attacks the seat base ply, it's a fully encased separate pc the then decking. So it aids in the prevention of rot spreading into the deck. It's fully wrapped w CSM & resin, mounted to the deck w/ out fasteners, PB or PL. Then filleted, tabbed & glassed fully to the deck.

WOG did something similar but used larger pyramids to accommodate his style of seat base pedestal. His is low cost because you won't have to purchase an actual pedestal for the seats (which can run well over $100 per, just for the base pc & post, NO seat).

The short pedestal & base I would like to use are $120+/- per and because I need them to be under 6", they are hard to find. I currently am reusing seats & pedestals that came on the Jet aluminum so totally a different style of build), just reinstalling them on a better bench plank. Friscoboater used the extra layer of ply as I have tried to explain it. I don't remember if it was in both of his threads, or which one. You might find it quicker looking through his YouTube videos.

Not that the T-nuts from behind wouldn't also be a good idea, but then you've opened an entire hole through your deck. It will also require very careful placement of the unlaid ply to layout the T-nut holes & then careful re-alignment of the ply at installation to the stringers.

You could also use the T-nuts in the 2nd layer of ply method I described in the beginning.... But they'd be in the back of the 2nd layer, which if ever needed to be removed, could be ground off & there would have been no penetration of the glassed in deck.

 

[hoffmanuno]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

I've read that Marine Grade Plywood encapsulated in epoxy works great and lasts forever while regular plywood encapsulated in epoxy has a much higher possibility of rotting away. I originally wanted to use 1/4 inch plywood for the floor and then coat it in a layer or two of fiberglass. That was what it appeared the old floor was made up of, but almost all the wood rotted away from it over time. If its only $20 more or so for a sheet of marine, I'd rather use it since I only need one full sheet of it anyway. My buddy and I bought this boat back in 2001 for $275 with the trailer and after he saw that it needed a major restore he basically gave it to me and I've been slowly working on it over the years ever since. I bought an old 1963 850 Kiekauffer merc for it for $50 and rebuilt the motor and lower unit years ago, and now I've decided to fix it up right. It's a good little boat and I like the way it handles in the water. I think I just might have this boat for another 30 years because its a perfect little ski boat and it's all I need right now and pulls great behind my old CJ7 that I restored from the ground up. I have a tendency to build things up stronger than the factory made them, so putting a little more money or blood and sweat into something to make sure it lasts forever is worth it to me. I figure for around $300 I can rebuild the floor, fill it with foam, and make it so I won't have to worry about it ever again. Besides, it will give me the life lesson of learning how to do this on a much larger scale if I ever buy a pontoon boat or small houseboat someday. I like learning how to fix things and to do them the best way possible.

Well, maybe instead of using t-nuts I can epoxy in some stainless bolts to the floor to secure the seats down with. I'll definitely look into your suggestion of mounting the seats to a section of board glued to the deck as well.

 

[Woodonglass]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

I'd recommend 1/2" for the deck. If you can find MG plywood for $20 bucks more than ext. grade then by all means buy it. I'd really recommend the pedestals for your seats...

Something like these would work great for your boat. If you use epoxy it will take more than $300 to redeck the boat. The Only way water can rot the wood once it's been encapsulted with resin, is if you don't always predrill and coat any holes with sealant. You boat is made from Polyester Resin and using Poly will be just fine. Now, if you don't want to use glass then you have to use epoxy. Poly resin by itself is worhless. Epoxy can just be coated on the wood with 2-3 coats and you're good to go except it must be painted. Just remember Epoxy will adhere to almost anything, but Polyester resin will NOT stick to epoxy.

 

[Yacht Dr.]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

I think your on the right track mate..

MG and Epoxy ( you mentioned West System ) would be how I would do it. I mean.. if it was my boat that was gonna be a keeper I would use the materials you suggested.

Stay away from T-nuts .. they are crap for boats IMHO. Try to through bolt whenever possible.

Your Trans can be filled up with the composites out there .. you just have to make sure the Whole trans is solid with the hull sides and hull bottom ( you may or may not need some struts going from the bottom to the inside of the transom ) ( got more pics .. ).

I think I know what your doing..and how you want to do it.

Epoxy has Much longer working time then Poly or VE .. it might be better for you to learn with longer pot life and buck up more $ than to work quick and screw something up. IMHO ..

More pics please.

YD.

 

[hoffmanuno]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

I thought about pedestal seats for the boat in the rear, but I already bought some new fold out seats a couple of years ago and I really like the fact that you can fold them down to layout on them.

Maybe you guys are right about just coating the boards in fiberglass and then gluing them into the hollow stringers and then glassing them into the hull. a 4x8 sheet of Marine grade 1/2 inch plywood is $50. Its about twice as much as regular plywood, but should give a lot more protection than regular plywood in the event that some of the poly coating cracked or was somehow penetrated. I feel more comfortable using marine grade from the transom up to the front edge of the seats. The last two feet I'll just use regular treated plywood encapsulated in fiberglass since it'll be in the last 1/3rd of the boat and always above water anyway.

The Transom is completely rotted out. I'm going to take the top of the boat off and then remove the rotted transom board completely. I know I could just put in a couple of 3/4 inch pieces of plywood glued/screwed together and encapsulated in fiberglass, but I feel more comfortable using a poured epoxy there if I can do it for under a $100 because of all the drain holes, screw holes for the handles, and other various holes above and below the waterline on the transom that could easily cause rot if the screws corroded or weren't sealed right. I'd rather just use an epoxy and sleep tight knowing that there was no way it would ever rot again.

I think I'll test drill into all the fiberglassed over boards used in making the boat's frame around the outside edges just to make sure they are ok and then glass back over the holes. There is one rear stringer I will have to replace that braces the back of the boat just in front of the drain. That won't be too hard to replace and I'll just glass that up too before I reinstall it.

I do want to run over the cost of fiberglassing vs epoxy coating before I commit to anything. It's a small enough job for me that I can fiberglass over the boards in a day on the saw horses in my garage before installing it the next day.

Here's some pics that I took today.

 

[hoffmanuno]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

I now have all the screws holding the top of the boat off and the top lifted up high enough off the back to get to the transom. Only the top fin parts of the transom weren't rotted and wet. I tried digging the top part out in chunks by hand and with a long chisel but it was too hard. I'm going to use my chainsaw to loosen it all up and then suck it all out with my shop vac. I'm thinking the nida-bond will work well for to replace the transom. I've heard that you should clean out the transom area really well and coat the interior of it with a thin layer of matting and resin in order to ensure the nitabond gets a good adhesive bond to it though.

 

[hoffmanuno]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

Well, after a fun filled weekend with my girlfriend at Warrior Dash up near Des Moines, I got right back to working on the boat when I got back. I used a chainsaw to get the transom out just like I've read on many posts about transom removal. The transom has been in the sun for the last 6-8 weeks in 90-105 degree temperature and was still soaking wet. I even left it exposed directly to the sun with the cap off for days and it only dried out the very top edges of it. The chainsaw went through it like butter. the top third of the transom was wet mush with a few somewhat hard layers in between. Funnily enough, the last 6-8 inches of wood along the bottom are turning out to be the hardest. The bottom of the transom wood is wet, but it's not really rotten like the upper 2/3's was. Considering my buddy found this boat abandoned in a farm field covered in black mold, I guess I'm lucky that the boat is really is such amazing shape for the amount of neglect it received. Here's some pics of it.
http://www.facebook.com/photo.php?f...0357366047663.360167.598332662&type=1&theater
http://www.facebook.com/photo.php?f...0357366047663.360167.598332662&type=1&theater
http://www.facebook.com/photo.php?f...0357366047663.360167.598332662&type=1&theater

I caught the outer skin with the chainsaw in a few places and just chewed through a bit, but nothing that can't be fixed with a little fiberglass patching before I pour the Nida-Bond. The outer transom skin seems to be warped/stretched a little, as it appears bowed out compared to the inner skin. I wonder that even after I put in spacers if it won't straighten right. I think I'll have to be prepared to make a cut down the center to relieve the pressure from the bowing/stretching if I can form it straight again.

I noticed that the inner drain hole for under the deck is only directly across from the outer drain hole/plug. To me this looks like water could collect on the sides and not drain out of the boat. Looking at this, I came across a plan to fix this and seal the boat. I want to seal the underside of the deck off completely. Not permanently, but make it more of like a sealed ballast area. I plan on using three threaded recessed drain plugs with o-ring seals on the front and sides of the drain area. I will keep the outer drain plug the normal style, however. I want to fill the bottom of the boat with expanding foam, except in the center channel for the main drain, and then make a small space clear of foam directly behind the side drain tubes as well, maybe make a channel out of the fiberglass resin with a few holes in it. This way water can drain out the back and front in case of a hull rupture or floor leak but keep any water from back flowing its way into the bottom of the boat. I know this sounds like overkill but I want a boat that is safe, will impress my future kids and grandkids someday, and will not sink even if swamped or it some horrible underwater obstruction.

I already ordered two 5 gallon buckets of Nida-Bond to pour the transom, which is about 3 gallons more than I should need. The Nida-Bond should seal up the transom completely and combined with glassing closed and sealing up the floor of my boat I think that I should be able to keep water out from under my boat unless I have a hull rupture, in which case the plugs will allow me to drain out the boat and repair it. I tend to overbuild things, but I think I will have one of the safest boats on the water when I get done with it and wont' be afraid to take it out on large lakes filled with crazy boaters leaving massive wakes.

 

[hoffmanuno]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

Last night I realized that my chainsaw bar was about 5 inches too short to reach the very bottom of the transom, and after a couple of hours of trying to dig the very bottom out and barely cutting through the outer skin of the transom on the back, bottom, and sides in a handful of places I gave up and just took off the outer skin about 3 inches back from the edge. The outer skin was bowed out and weaker than the inner transom wall anyway, so no big loss. After I did that I could easily chainsaw my way into what was left and then lift out the last pieces in large chunks. It looks like the old transom was cut and beveled perfectly into place but then just coated in resin and stuck into it. The transom was stiffer on the bottom, but still soaking wet and rotting. Here are some pics of it removed.

My plan now is to clean up the transom area and cutout with sandpaper, clean with some heavy duty marine cleaner, wipe down with some thinner or acetone on a rag, and then prepare a few small spacers from resin or pvc. I will then patch any cut through on the inside of the transom from the chainsaw with fiberglass matting and resin, then coat the inside of the transom cutout with resin and a layer or tow of matting to strengthen it up and reinstall it by bolting it back on with the spacers to line it up perfectly and glass it back on from the inside with a layer and then layers of glass on the outside edge until its strong. This should get me ready to pour my Nida-Bond when I pick it up from the dealer in the next week or two.

 

[Woodonglass]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

The nidabond was much more than your budget of $100 wasn't it?? Cutting the outside skin of the boat has complicated the issue. Your boat was Poured in a mold as a one piece unit, therefore making it strong. You will now have to attempt to use glass to strengthen it back to the point it was. It will take some time and effort to do this correctly. the transom is one of the most critical structural components of the boat and must be sound to ensure the safety of the craft. Not saying it can't be done this way, just that it's usually avoided as much as possible. You could have removed the lower half of the wood using a drill and fabricating an extension for it and using modified spade bits. It's done quite a bit this way. It's your boat and you can do as you wish but taking your time and seeking advice from experienced people will help to ensure that the boat is restored properly. Just my 2?

 

[hoffmanuno]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

Yep, the Nidabond cost me $325, but I'll have a few gallons left over that I'll either use on my boat or sell for cheap to somebody working on their boat that needs it. When I got down to the bottom of the boat I realized that I could make my own tools to do it or pour in some acid to dissolve the wood, but the outer transom skin was so weak and bowed out from the rotten water logged wood that I realized I needed to cut it out anyway in order to straighten it our and reinforce it a bit. I crunched the numbers on buying two sheets of Marine Grade wood to do the transom and gluing them together for the 1.5 inch transom and then glass it over and it came to roughly half the cost of the Nidabond.

One thing I learned rebuilding my Jeep CJ-7 from the ground up is to take advantage of newer technologies and chemical applications because they can make your vehicle last forever (I documented it with pics on my Facebook page). I used a chemical called POR-15 to treat my rusted frame and body in my jeep and for the last few years I haven't had a lick of rust on any areas I prepped correctly, so it will likely last forever. I look at projects a lot differently after that. The POR-15 cost two times more than everything else but worked great and even a lot of antique car restoration enthusiasts were finally starting to use it after scoffing at it.

I also have an old 1963 Merc 850 tower that is rated 10hp over my boat, so the extra strong transom should make sure I never have a problem with it again. I know a fiberglass encased wood transom would last a very long time, even decades, but I also know that for a little more money I can have a permanent fix that I feel confident will outlive me or whoever eventually inherits my boat in the future. I've worked with fiberglass a lot restoring my completely cracked jeep hard top that was missing a chunk the size of a cantaloupe and managed to put that wobbly thing back together to the point you can't even tell it was ever broken. Cutting the back off will actually make it easier for me to align the spacers now as I can glue them on and then clamp it in place after the transom is ready for the pour.

 

[hoffmanuno]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

I really do appreciate the comments and any advice that everyone has to give me. I am constantly pouring over old posts from people doing similar rebuilds to mine and I've noticed that everyone tends to do their project slightly differently, but they all tend to do a heck of a job by the time they are done. Although I didn't want to cut into the transom in the first place, I realized after digging out all the rotten wood that it would be much easier to prep the cavity for either wood or Nidabond/Seacast type material in order to remove all the loose fiberglass resin, rotted wood, and other contaminants.

I really have to thank the many people on this site and others for posting their own projects and comments in order to help me along with mine. I hope that as I keep posting pics and details of my project, along with your comments, will help others in their projects too. Besides, I simply love rebuilding old broken things!

 

[hoffmanuno]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

Last night I finished cutting the remainder of the lip of the old deck off the boat. I left about an 1/8 of an inch of the lip on the sides of the boat because I didn't want to cut into the hull with my grinder and it should give me a mark to match up the new deck to when I go to put it in. I only glanced into the surface of the inner hull in a handful of areas and did no real damage, so if anything I might just put a small piece of fiberglass matting over them, but I really don't think it'll be necessary. I decided to cut out the old drain well as it seemed to be poorly constructed. The bottom of it is full of resin and wavy and the sides were massively thick and bowed out a bit. I'm just going to form it up with some thinly glassed over boards and put the deck on it, then I'll glass over it for the new one. I'll need to make sure that the hollow glass keel stringer connects to the drain hole and that the expanding foam won't get into it and block any possible drainage. I think I'll just make sure the glass goes straight to the board with the hole and inner drain plug and that should keep out the foam. Here's a pick of it.

As I was trimming out the edges of the floor in the bow of the boat I ran into an air pocket. I was puzzled and after getting chased out by a wasp I came back and vacuumed up the wasp and nest along with the fiberglass dust and debris to get a cleaner look. There was a small space along the keel/hollow glass stringer that ran into the enclosed bow area. It was full of soaked mouse nesting. This boat was abandoned in a field for about 20 years or so without a drain plug and I've been finding pieces of old bright blue deck carpet, walnuts, and other bedding all over under the deck. Amazingly the mice didn't like the fiberglass one bit, so its solid, but the boat's under floor area was like a mouse farm and those hollow glass stringers made great homes for them.

I didn't want to cut into the stringer/keel to clean it out so I cut a small square of the bulkhead area out above the stringer and started to vacuum it out. I probably got most of a 5 gallon bucket's worth of soaked mouse bedding out of there. Its also clogging up the keel/hollow stringer that heads directly back to the drain. I'm going to let it dry for a day or two and see if I can then suck it out easier by pushing into it with and old hose. I will also be power washing the bulkhead and stringers when I'm done vacuuming and cleaning the inside of the boat. I want to make sure everything is clean before I begin glassing repairs and putting in the floor. Nothing would bother me more than knowing there is another 50lbs of wet mouse bedding under my deck after I get done fixing it. I'm not worried about the piece I cut out of the bulkhead as I'll just glass it back in and will be filling that area with floatation foam. Here's a pick of it.

 

[Yacht Dr.]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

I suggest glass wrapping the outside skin of the transom to the hullsides. Just 3" of tabbed glass ( If its indeed 3" ) on the transom only is way too close for comfort. Wrap the sides 6-8" with glass IMO.

You will basically end up with a one sided glassed transom ( inside ) to support the load of the motor and the energy involved.

Think of a shoe box .. try to push the lid into the box.. kinda hard right ? Now take that same shoe box and invert the lid so it sleeves into the box.. now push on it. Goes right in the box right. What your doing is inverting the lid and putting some tape on the edges of the lid to your box. The lid is still strong but your tape is only a fraction of what it takes to make another shoe box.

Hope you understand.

YD.

 

[hoffmanuno]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

Yep. I understand you perfectly. I need to build up some of the nicked up sections of the inside of the transom from getting the wood out. The back of the skin was practically no fiberglass at all, it was maybe a third of the amount of fiberglass as the inside of the transom skin, which I thought was bass ackwards compared to the way most people describe there's and how it is supposed to look. It was so weak that it bowed out from 1.5 inches on the sides to almost 3 inches in the middle of the transom. The inside transom skin was taut and straight, however. The back edges of the boat had taken some hits and were cracked before we bought it 11 years ago and I had done some fiberglass repairs on it to get it seaworthy before, so now is the perfect time to seal that all up by wrapping it up around the sides of the hull. I might as well do the bottom too while I'm at it. I was considering reglassing the entire back end in a couple more sheets of fiberglass anyway, since it was so weak and thin. It shouldn't effect how my brackets or outboard mount on the transom anyway I'd think.

Thanks for the input! I'm thinking that I shouldn't do any serious outer fiberglassing of the outer transom until after the Nida-Bond pour though, just do the seams with a few strips of fiberglass to fill the edges in and strengthen it for the pour and then sand the whole thing down and fiberglass it all in good after the Nida-Bond has set up.

 

[hoffmanuno]

Re: Hollow glass stringers?

Re: Hollow glass stringers?

So last night I was vacuuming out the remaining mouse nest material from the bow and around the other hollow glass stringers when I hit a piece of wood stringer between the port and starboard sides of the boat. There was originally a board across the bottom parallel to the transom that I believed was just used to help form in the drain well that was almost completely gone. It was not glassed in, but held in with a few glass overlays every 6 inches or so. The ones further up the boat that join the hollow glass stringers together were not glassed in either, but they were loosely covered in layers of fiberglass matting and woven that overlapped each side of the stringer by about 6 inches. I think these boards are not structural, since they were not completely glassed in and move easily inside the stringer when I hit it with a screw driver. I think that these boards were themselves just used as forms for the fiberglass matting in order to join the hollow glass sections together and then nail in the floor of the boat to be glassed in. I've seen rusted out tiny nails in them with small clumps of the old wood floor around them, so that's my working theory.

So am I correct in then assuming that since they were never firmly glassed in that I don't need to replace them? The fiberglass is VERY solid on those areas, actually its the firmest part of the floor. I'd rather not rip them up just to replace the boards if they weren't structural and have no problem leaving them in there because once I seal up the deck they shouldn't get wet or cause any damage. I'd hate to weaken the structure just to remove them.

The only weak areas of the floor are places where a decade ago I sunk in some bolts with resin and fiberglass to hold the seats down. That ripped up an inch or two wide section of the glass in 3 places, but I will put the mat and then woven over it to strengthen it back up and it should be good as new.

I'm having problems getting all of the mouse nest material and walnuts out of the boat floor. Its hard to reach into the hollow glass stringers because they are almost all sealed up tight with little to no access to them. I'm thinking of power washing the boat floor out when I'm done grinding away and trying to use the water to flush all that crap out as much as I can. I know that I have the majority of it out now, but there's sitll a lot left in there and I don't want it in there moist and soaking up water in the even of a small leak. I'm gong to be filling up all the open voids I can with floatation foam as well to firm up the bottom/floor and keep the boat from sinking in the event of a swamp/leak so I'd like to get all the crap out of them before I pour expansion foam into the hollow stringers.

Should I just use regular flotation expansion foam for the entire floor or try and use a small amount of structural expansion foam for the inside of the stringers? The floor is very firm so I'm not worried about any possible structural weakness now. I think using structural foam would be overkill and unnecessary at this point anyway. I will be leaving the main stringer along the keel hollow for drainage so water could drain its way back from the bow in case of a leak.