67 - 22'2 Flatback Diver Rebuild

[gman 82 aquasport]

Thank goodness for structural foam , you've got a good start, it might seem like it will never end, but it does and you will not regret redoing your stringers since they were loose anyway Once you get everything cut loose and get the hull ground down smooth, you are going to pick up speed with the rebuild...just keep up the good work, it will be done before you know it

[OldSkool67]

Well after much grinding I still have much more to go and after that some more grinding.

Right!

Go ahead and get her right. Lord knows there are a bunch of good examples here. All of our Proline rebuilds have new stringers, some nice work too.

No biggee...let us know which style you choose.

Gran and Rickk Im going to do something similar to Lilrichards stringer set up. I will start to work the details out after I get my grinding all done... so sometime in 2014 I should be able to order the stringer material :!:

OS - Following this project with much interest.  Best of luck on the results.  Appreciate all the photos you've been able to share.  Hope you've even got more on the hard drive at home.  This is a great R&D expose on the one of the hulls that inspired this site.  

Sorry the stringers are toast, but at least you'll know what you're standing/floating on when it's all over.  Try to keep the momentum.  From what I've experienced and read, that's the key!!!  That and a sufficient supply of good ol' fashioned greenbacks.  

Thanks Georgie. Im pretty good at keeping on a project till its done and I made sure I had a good surplus of cash to dump into it before I started so that I wouldnt stall along the way. The stringers are just going to eliminate some sweet toys off the back side of the project IE: Side imaging sonar and the kegerator.  :cry:

Oh mannnnn - you're past the point of no return.  
The way they set the stringer "insert" was pretty bad - at least on mine. Seems they made the stringers up with roven between them for spacing and then dropped the whole thing in and pasted it in.  That's how mine was and most of the insert was loose somewhere.
So how thick do you think the stringer sides were - maybe 1/16"? How about the tops -maybe 1/4"?  Amazing how little was there - guess that's all it needed?
Can you take some pics of the thickness with a ruler showing the thickness - good for history.  
I remember reading that the trapizoid stringer actually gives you 2 stringers instead one for each one because of the sides - but as thin as they were....

Rickk you are correct on your estimatations.. the pasting it in part is the worst, I have the epoxy paste everywhere and its close to a inch thick in some spots. Its a real pain to get it ground out. My 74 was nothing like this and looking at pictures of other rebuilds I dont seem to see anyone with as much paste and filler as I have.. maybe Im just lucky.

I didnt get any pictures, they were all hauled out with trash pretty much right away.

Thank goodness for structural foam , you've got a good start, it might seem like it will never end, but it does and you will not regret redoing your stringers since they were loose anyway Once you get everything cut loose and get the hull ground down smooth, you are going to pick up speed with the rebuild...just keep up the good work, it will be done before you know it

Thanks

[OldSkool67]

Looking for some feedback on the center of the hull. As I said before there is tons of this epoxy/resin paste everywhere and extremely thick. I have chiseled off all of the loose material and grinded alot of other spots. It will take me literaly 20 man hours at least and will probably burn up a grinder or two to grind that section out. Its definitely not delaminating back there.

My intention is to lay a few layers of glass through out the entire hull and up through the chines.

Thoughts and opinions?


these are some areas in the front that I have grinded down smooth



some more areas I have ground down.

this is the trouble are Im not sure what to do with.

[gran398]

Man, we're feeling for ya :(

The way that epoxy is...it's gonna be darn near impossible to remove every trace. You may have to stick with epoxy there, and shift to polyester for the places they didn't epoxy when you start the glass work.

Question: What is that bolt looking thing, what does it do, where does it go? My flatback has the same looking thing, it is located about amidships, and is imbedded in the deck.

[dirtwheelsfl]

Sure its epoxy?  See if it smells like the rest of the hull when youre grinding it, epoxy will smell different. If its bonded well just get it even with the rest of the hull and leave it. Ive got an 8" makita grinder that weighs about 30# and does 14000 rpm if you wanna cross the state to borrow it. Cast iron, thing is scary! Knock that hole bottom out in half an hour..

[OldSkool67]

Sure its epoxy?  See if it smells like the rest of the hull when youre grinding it, epoxy will smell different. If its bonded well just get it even with the rest of the hull and leave it. Ive got an 8" makita grinder that weighs about 30# and does 14000 rpm if you wanna cross the state to borrow it. Cast iron, thing is scary! Knock that hole bottom out in half an hour..

it stinks when you are ginding it... smells like crap, literaly like crap when you grind it. That was one of the first things I noticed.There are two different materials one is white and much like a concrete type product, very gritty. Then a black epoxy like substance. Both are a pain to grind out and lots of it.

I thought about trying to rent something like that next weekend... figured 100 bucks in rental is cheaper then my time at this point. I have a couple makitas and dewalts and Im gonna burn them up at this pace.

Man, we're feeling for ya :(

The way that epoxy is...it's gonna be darn near impossible to remove every trace. You may have to stick with epoxy there, and shift to polyester for the places they didn't epoxy when you start the glass work.

Question: What is that bolt looking thing, what does it do, where does it go? My flatback has the same looking thing, it is located about amidships, and is imbedded in the deck.

it was a drain in the fishbox in front of the gas tank.

[seabob4]

Ryan,
Just an opinion here, but one you may like to hear.

That "stuff" on the hull bottom, be it epoxy, vulcan death grip material from hell, whatever it is...it's not going anywhere.  So fair it as best as possible to the hull bottom contours and call it a day.  The real kicker is that you want the glass you put down to adhere.  From what I understand, epoxy is not a good substrate when trying to bond materials to it.  I would have to think that if an epoxy surface is roughened up to a certain degree, say, using 36 grit paper, it will accept a bond.  So with a little bit of effort and $$, glass the hull bottom to give yourself a good starting point, then proceed as planned.

You'll be able to tell whether the glass adheres to those areas after a couple days, when it's really had time to kick off and more or less become permanant.  If it feels good, run with it.  If not, plan B time.  And God knows WTF that is!

[dirtwheelsfl]

Yea, id rent a grinder if you could. Bigger one will do a better more even job too...

[dirtwheelsfl]

Here she is..  I call her "Rosie".

[Aswaff400]

that area is the same spot that took me forever to grind out, i think i went through 3 36 grit flapper discs in that area.  

[gman 82 aquasport]

Rent you a grinder/sander and see if you can get some 24 grit disc, feels like small gravel but it takes the bad stuff off a little faster..

[LilRichard]

I'm with DirtWheels... get yourself a big ass grinder and 24 grit disks... it'll make that an easy task.  

And if it is epoxy, you should stay epoxy for the build.  I don't mind polyester (I did my build with it), but I am not a fan of mixing products.  Stick with one.

[Georgie]

As an additive thought to Richard's ...

And if it is epoxy, you should stay epoxy for the build. I don't mind polyester (I did my build with it), but I am not a fan of mixing products. Stick with one.

From what I've seen on rebuild posts, and from what little work I've done myself, the finished floor actually isn't glassed to the stringers and is merely supported and bonded via separate adhesive in most instances.  As such, is there any reason why it wouldn't make sense to use epoxy for strength and adhesion during stringer re-fabrication (especially given the old epoxy "contamination" Ryan has and delam issues we've seen in many of the older boats from flexing and age), but then switch to poly when installing the floor or doing additional topside work?  I would think it would save some $$ over using epoxy thoughout, and also provide the builder the added advantage of being able to use any finish coat he desires.  (Using epoxy all but eliminates gel-coat as a finish option unless you go through the pain and expense of multiple vinyl-ester primer coats in between (I have three small areas in my wellcraft transom where the new gelcoat never cured properly despite laborious care during the prep stages)...hence why Richard's saying stick with one product.  Kind of a rambling question, but I've been wondering about this for a while.

[RickK]

And if it is epoxy, you should stay epoxy for the build.  I don't mind polyester (I did my build with it), but I am not a fan of mixing products.  Stick with one.

I read your topic end to end trying to find out what you used and not one time did you mention what you were using for resin (that I could find) so I assumed that you were using epoxy since you got a lot of advice from Joel and Wart who are both epoxy guys.
I think I will use a mix of the two - poly to make the stringers, epoxy to lay a complete layer of cloth on the inside of the hull for a good secondary bond, epoxy to attach the stringers and then go back to poly for deck and above. Epoxy is just so damn expensive  
BTW - check your PMs

[GoneFission]

Man, we're feeling for ya :(

The way that epoxy is...it's gonna be darn near impossible to remove every trace. You may have to stick with epoxy there, and shift to polyester for the places they didn't epoxy when you start the glass work.
Question: What is that bolt looking thing, what does it do, where does it go? My flatback has the same looking thing, it is located about amidships, and is imbedded in the deck.

Likely for a grounding plate...