1980 19-6 rebuild

[love2fish]

no that shouldn't be a problem. my tower is around 7' to the top (from the deck) and I have minimal extra sway because of it. Nothing I have noticed or that outweighs the benefits of the tower.

[Blue Agave]

I recommend a console with a helm. 99% of your driving will be done from the lower station.

[Capt.Andy19]

So my stringers are delaminating from the hull. Would you guys rip them out and put in composite beams like thennutts rebuild? If so what material would you use. I plan on adding a tower and having a lot of weight in the boat. Plus a 175-225 hp on the back

[love2fish]

depends: how bad are they delaminating? need to decide if it is more worth your time/money/energy to clean up the existing stringers, (grinding the delaminated areas and re-glassing, then refilling the stringers with dry 4lb foam (at which time you could raise them to the desired height), and then re-decking,,,, or cut everything out, grind the whole hull, buy new materials, and lay a new stringer grid.

do some more research on build threads, you can look at flatbacks, 22-2 ospreys, and 196's for reference, as all have similar design/build processes (some flatbacks have the original (stringer layer which is nothing like what you have, but several of those owners have pulled them and gone back with new stringers)

[Capt.Andy19]

so i think im going to refoam the existing stringers unless you guys suggest otherwise. How do i go about reglassing them to the hull? do i have to do the inside and outside of each of the "walls"? also do i have to replace the wood that was on the "wall" of the stringers? do i need to brace the stringers when pouring the foam so the foam doesn't break them off? just an fyi i have so many questions because i have never fiberglassed before... i have been told that for this project i should use poly instead of epoxy because of cost, applying gel coat after and that i want to stick with the same material that was originally used in 1980 which was poly... any suggestions or ideas are appreciated!

[RickK]

If you want to salvage the stringers (they look in good shape but the bond to the hull is weak), you have a couple options - grind or sand blast.
If you have access to a sand blaster you might consider using that to blast the inside walls of the stringers and hull inside the stringers.  That will make the work much easier.  If you can't, go buy a cheap 4" grinder at harbor freight and buy some 40 and 60 grit flap sanding wheels.  That's small enough to get inside the stringers. After you blast or grind the inside of the stringers and get ready to tab them back into the hull I would cut some 2" strips that I would glass over the tops of the stringers to help them keep their form.  For the cracks along the bottom in the places you showed, after you tab the insides, I'd lightly grind the cracked areas and lam some 1708 over them. the stringer bond strength is now inside the stringers, so the outside is more making them one piece again.
As for which resin to use, you are trying to get the best bond you can for the stringers - so I'd use epoxy there.  Yes it's more expensive but it is like 100 times stronger in secondary bonding than poly.  You have plenty of evidence of how poly holds up. Plus you can count on epoxy bonding to the areas of the inside of the stringers that you might not get quite roughed up enough that you would need for a good bond from Poly.  Epoxy is a better choice of resin, for sure.  If you are going to re-gelcoat, I would use epoxy below the floor and poly above.  If you're going to paint, I would use epoxy throughout.

I would prep and re-tab the stringers to the hull but not foam them until you decide what you are going to do with the transom and how high you want to raise the floor and how you are going to handle the new height and how to tie them into the liner sides and casting deck.
Spend some time looking through the Rebuilds forums to see how other people have approached the same thing you're going through.

If you don't want to salvage the stringers they will probably come out pretty easy with a pry bar.  Then you have the whole hull to grind.

[Capt.Andy19]

Have you blasted a hull before or know anyone who has? I've read mixed things about it. I would definitely do it for the ease and speed compared to grinding but I just don't want to ruin the hull...

[RickK]

I have not. I cut my stringers out, gutted the boat, ground the hull, lam'd a couple layers of 1708 over the hull inside and started over.
We have several members that did sand blast the inside of their boats with good results.  You're going to have to dig through the  topics via the search function. Most sand blasting nightmares you hear about are on the outside of the hull.

Here's some of the many links: (click on the "search menu" in the middle of the upper bar and type in sandblast)
Aaron did some of his boat by sandblasting
http://classicaquasport.com/smf/index.php?topic=9842.msg86077#msg86077

Matt did his flattie inside
http://classicaquasport.com/smf/index.php?topic=7601.msg59954#msg59954

Mitch did also
http://classicaquasport.com/smf/index.php?topic=10352.msg101869#msg101869

[Capt.Andy19]

ive been told by some people that i need to run bunks along the length of the hull, like trailer bunks before moving forward so i dont distort the hull... any comments? i currently have t supported on this. it fits the back of the boat perfect along the v and the bow is supported on the keel and the support you can see. let me know ASAP to prevent damage!!!

[RickK]

  I think you're ok. If you walk around in the hull and feel movement rethink the cradle and make sure the centers are supported.

[Capt.Andy19]

what kind of grinding discs do i need to prep the glass and remove the stuff from the stringers? also i have no idea how much material im going to need and have found it is going to be cheaper to buy it all in bulk first! so what would you say i need? im planning on using poly...

[RickK]

Flat flap discs - like this - http://www.sparkyabrasives.com/Item--i-FD7__45__Z060?utm_source=google&utm_medium=cpc&utm_campaign=PLA&scid=scplp7824382&sc_intid=FD7-45-Z060&gclid=CPmE-MSIm88CFYgmhgodxgYNiQ

If you're going to go with poly remember that poly starts hardening from the minute it is made, so don't buy too much in advance. Find a place locally to purchase it if possible.
For the fiberglass, the cloth and mat comes in 38" or 50" wide goods.

[Capt.Andy19]

what kind of glass would you guys get/use? im thinking mainly 1708 and 1 1/2 CSM. maybe some 6 oz mat for the final layer on floor???

[mshugg]

The 1708 is good for structural reenforcement, tabs, transom, deck.  It already has mat on one side. 

The CSM is good for increasing the bond between transom layers or when joining transom core to the old skin, or as a final cosmetic layer where fairing is important.  But other than that, it adds weight and thickness without adding much strength.

[dirtwheelsfl]

My go to grinding setup is a thick rubber backer, then a thin phenolic backer, followed by 5" disc (36 or 50 grit)

http://www.usatoolwarehouse.com/usatoolwarehouse/MWK-49-36-3500.html?gclid=CJimiNP2o88CFQgehgodYZQPZg

http://www.usatoolwarehouse.com/usatoolwarehouse/SGT-94720.html


Really helps keep it flat and less gougy...