69 flatback rebuild

[Capt Matt]

I began stripping my 69 flatback down the last few days. The cap is off, floor out and foam removed. Does anyone know how to remove the bedding compound on top of the stringers? I want to cut the tops off the stringers and re foam them as they are in good shape and not delaminated.  All the foam that came out the boat was wet.
Any info would be great
Thanks
Matt

[Skoot]

not sure myself, but would love to see some pics

[slvrlng]

In looking at old posts, it seems the quickest way is just to grind the bedding compound off.
Messy, yes but quick. Is the stuff on top similar to concrete?
You could chisel it off but unless you're good with an air hammer I would be extremely careful.

[gran398]

Lew, think you're right....take a 40 grit pad and an angle grinder, and have at it. AND a respirator.

[Capt Matt]

http://s836.photobucket.com/albums/zz28 ... g&newest=1

http://s836.photobucket.com/albums/zz28 ... g&newest=1

http://s836.photobucket.com/albums/zz28 ... g&newest=1

Here are the pictures of my project. Its in the early stages of stripping down but any info will be greatly appreiciated.

I have been following this site for a while and found this boat on here after about 3 months of looking for the right flatback to restore to be my new guide boat.

Thanks for the input
Matt

[Capt Matt]

Started cutting the tops out of the stringers today, even though the foam looked dry on top it was wet underneath. Anyone have any idea's on how to cut the tops out of the side stringers that run against the hull? I'm worried about cutting the fiberglass mat tabs that hold the gunnel to the side stringers

Thanks
Matt

[thennutts]

Started cutting the tops out of the stringers today, even though the foam looked dry on top it was wet underneath. Anyone have any idea's on how to cut the tops out of the side stringers that run against the hull? I'm worried about cutting the fiberglass mat tabs that hold the gunnel to the side stringers

Thanks
Matt

Matt,

Go ahead and cut the edge of that outer stringer with an angle grinder at a slight angle following the hull curve. If you are worried about interfering with the tabbing, don't be. Regardless you have to re-glass those stringers after re-foaming them. If it were my boat, after cleaning out all old wet material, id re-foam then I'd run a large strip of 2408 or multiple 1708, up 8" on the gunnels, down the gunnel, over the top of the stringer, down the stringer and onto the bottom of the hull at least 8" in one continuous run. Bring a friend and put a 4" paintbrush, large bubble buster and have gallons of resin ready, its gunna be a hell of a run!!!  

-Chris

[gran398]

There you go Chris, throw the beef in there. So how wide do you reckon that first piece will be?

[dbiscayne]

I'm going through what you're doing right now, just a few steps ahead of ya.
The bedding compound chipped off pretty easy, a lot easier than grinding it.  I used a pry bar, put the curved end at the base of the compound & smacked it with a big hammer, sent big chunks flying but not as messy as a grinder.

I'm raising my floor about an inch so I cut the complete tops off my stringers, no reason to chip off all the compound in my case I just cut along the side of the stringer at the very top & will have to build about an inch of vertical wall before going across the top.  Can't beat a sawzall for doin that.

To get the foam out I again used the sawzall with a long blade and carefully slid the blade between the foam & the stringer running down the length of the stringer, then cut across the foam about every 10 inches, letting the blade just barely tap the hull.  Came back with the pry bar & took out big square chunks of wet foam, first piece was tricky but the rest popped right out.  The blade didn't even leave a mark on the hull, just go slow.

I also cut the tops off the outer stringers & thought I'd be able to leave a little tab of the stringer still attached to the outer sides, but I wanted to wrap the new glass up the sides of the boat and the old tab ended up being in the way when I was trying to clean up the sides.  I used the circular saw & cut about a little more than an inch off the vertical wall of the inner side, letting the guard rest on what was left of the deck to make a nice straight cut, then ground the remaining stringer tab off of the side & plan on gluing a strip of foam to the side to support the new glass.

Before foaming the stringers I ran a 3 inch wide tape strip along the inside wall of each stringer where they meet the hull, with about 1 inch on the hull & 2 inches on the stringer.  From the factory they were only attached from the outside of the stringer.  Just this one layer of tape made the stringer a lot stiffer.

[thennutts]

There you go Chris, throw the beef in there. So how wide do you reckon that first piece will be?

Gran, id say that the piece would be approx 25"? Which would be perfect if you get 1708 in 50" roll. you get 2 layers with no waste. Can't beat that.

Capt matt,
A little advise. Instead of killing yourself and going back to your glass shop every week to get yards of material, do like I did, I bought an entire 209 lbs roll of it. Here was my savings 40 yrds 1708 cost me $440 dollasr OR by the 209# roll for $550. It is a no brainer. You get well over 125 yards on that roll. Just a suggestion. If you have left over, take it back to the shop and sell it back if you have that relationship with them or sell it on here!

[Capt Matt]

I cut the tops off the stringers and have been pulling out all the foam. A sawzall saves alot of time just cutting long strips up and down the foam then pulling it out with a claw hammer and a pull bar. I'm about 3/4 done. Been so hot out just doing a few hours in the morning then a few before sunset.
Most of the flatbacks I look at online have had the middle stringer removed so a fuel tank will fit in the floor. Should I remove this whole stringer or just shorten it up? 5 stringers wide seems like overkill anyway.  Looks like the bilge would drain better and be more accesable without the middle string too.
Thanks for your input
Matt

[LilRichard]

Most guys do remove the middle stringer - and the better rebuilds ad some bulkheads to tie the two innner stringers together at the front and rear of the tank - minimum.

[Capt Matt]

Got the boat up on blocks and under a tent to make a little shade at least. I just cannot decide if I want to remove the old stringers and go again or refill them. Its the thought of refoaming and that foam getting wet again somewhere down the line. I think i can build a better stringer system than the stock  pyramid style that I would need to raise up 2-3 inches anyway. With the boat almost totally gutted what are the advantages of saving the old stringers vs making new coosa board stringers and bulkheads?
thanks
Matt

[fitz73222]

Todays foam doesnt get waterlogged like yesterdays foam. A buddy of mine refoamed a Robalo some years ago and took a coring of the foam and put it in a sealed jar full of water and set it in his garage for 3 years completely submerged to see if it would absorb water and it never did! If there is no delamination of the stringer boxes, I would refoam the existing stringers. If you decide to make new ones you are going to have to make a jig superstructure to support the hull to keep it from flexing and folding once you remove the stringer "backbone". These boats had an excellent stringer system ahead of its time.

[Capt Matt]

Looking at lots of other rebuilds I have yet to see any pictures that they have raised the floor after refoaming the original stringers. It seems it would be as easy to just build new ones