Flatback Fireboat Rebuild

[CLM65]

Excellent, thank you Scott!  Does 1708 qualify as thick and rigid enough?  Or do I need to get something heavier?

[RickK]

4 layers of 1708 or 1808 is about 1/4".  You should tab with 2 layers.  1708 is a pain to go around a corner so it should be stiff enough to stay up against even a lightly inverted angle. Some people lay the wider layer on first and the thinner on second saying they control air bubbles better that way (I've tried both ways and it does seem to help) - I guess it really doesn't matter which is on top if you're wet on wet.

[gran398]

Excellent, thank you Scott!  Does 1708 qualify as thick and rigid enough?  Or do I need to get something heavier?

Called Chris back, he said 1708 will work great

What Rick says he reiterates regarding adhering to inverse angles. He also said if worked correctly, it will even adhere upside down.

[CLM65]

Thanks guys, two layers of 1708 it will be.  I'll also put down a layer of 3/4oz mat first.  I know most people will say that the mat sewn to the 1708 is good enough, and they may be right, but Eugene recommended a layer of mat first for better adhesion.  As long as it doesn't prevent the glass from staying in place, I think that is good advice.

[gran398]

That sounds like an excellent plan. Beefy layup low in the hull, strength and rigidity.

A little extra weight.... but exactly where you want it.

[CLM65]

A little bit further along...and a few more questions.  I picked up a 16 gallon freshwater tank for my rebuild.  About the only place it will fit easily is under the casting deck.  It's hard to tell in the pic below, but the front of my gas tank is a few inches back from the edge of the casting deck, so the water tank will start a few inches forward of the edge of the casting deck.  Is this going to be putting too much weight up front?  (the stringer that the tank is sitting on in the picture will obviously be cut down).  Also, what is typically done to vent the tank?  Would I use a gas vent high on the hull?  Or run the vent line to a thru hull lower on the hull?



Also, here are my knees glassed in.  They are 2 x 3/4" Kay-Cell, just like the transom, and will form the sides of the bilge.  I guess you can say I have hybrid stringers - part composite board and part foam/fiberglass.  I put 3" PVC rigging tubes at 45 degrees, one on each side.  I'm also going to put a couple smaller pipes through the bulkheads (between the center stringer and the stringers on either side of center) for the fuel line and anything else that will need to go between bilge and the tank area.  If anyone sees something I'm missing or doing wrong - it's not too late to let me know!!!

[Capt. Bob]

Craig,
One thought on the weight forward.

Less than 140 lbs with everything attached, completely full so....

It not unlike having a small adult up front when running and will make little difference when fishing.
Spreads the load rather than concentrating it aft.

I don't see it being a problem at all.

I probably have twice that forward in the cabin on my WAC. Rides very well thank you.

Worst case is the boat steers wildly and submarines on you so you just don't put as much (or none at all) water in the tank.

As one cut and paste to another, I will predict two events.
It will ride nice and smooth and you'll love the fresh water.

Rick has a 40 I believe. He should have a good read on the vent issue.

Good luck.

[RickK]

Hi Craig,
I'm interested in how the stringers will be tied together since it's a little confusing to me in the last pic with the empty originals and the new composites in the same pic.

As for venting the water tank I have in the 230 (40 gal), I had them install (had the tank made) a vent on the top of the tank that has a plastic bolt in it to open or close it.  I open it when drawing water from it via the pump and close it when cruising so I don't slosh water out of it.  As I get down to 3/4 tank and below I leave it open. Works great but I have easy access through the hatch in the back of my floor in front of the splashwell.  If yours is not going to be easily accessed you'll need to treat it like a fuel tank with a vent line.

As for location and weight forward I think a FB owner will have to reply since they would know how the boat acts with a big tank in it versus the above deck tank they had originally and how, by adding more weight forward, that would affect the bow steering those boats exhibit as it is.

[Capt. Bob]

As for location and weight forward I think a FB owner will have to reply since they would know how the boat acts with a big tank in it versus the above deck tank they had originally and how, by adding more weight forward, that would affect the bow steering those boats exhibit as it is.

You know, I didn't think about that but what really causes the "bow steer"? Is it the hull dead rise or weight placement? Stern slipping or bow digging in? Greater amount of hull surface in the water as opposed to other hull designs?

I re-read Hopefishing's Proline rebuild and he mentions the bow steer effect. It will be interesting to hear from the Captains that run a flat back as to where they have positioned their clients while underway and in different sea conditions to counter or reduce the effect.

Still think Craig will like the fresh water. Just have to grip the wheel a little tighter.

[gran398]

Haven't heard from Matt in a while, think I'll give him a call.

He runs his every day for a living, different weight scenarios, etc...

Will report

[gran398]

Matt said to put the freshwater tank under the center console if possible.


OT:

Captain Matt Fishing Report:

They are KILLING the snook.

He is repowering tomorrow with a 4 stroke 150 HP Merc.

[CLM65]

Good input Bob, Rick, and Scott (and Capt. Matt).  If I do put it up front, I guess I can leave it empty if it causes a problem.  I briefly looked at putting it under the console, between the gas tank and the bilge.  I know that will be tight, but I'll look at it again.  That may work.

Rick, I know it's hard to visualize what my stringers will look like from that pic and the fact that the stringers are currently open.  This may help.  The dark border of the bilge is going to be Kay-Cell, while the hatched lines show the foam filled stringers.

[Blue Agave]

Keep in mind one can compensate for a stern heavy boat with trim tabs. There is no device I know of that will compensate for a bow heavy boat.  

[CLM65]

Took some measurements and it looks like the water tank will fit between the gas tank and the bilge .  It wouldn't actually be under the console, as there is only about a foot between the back of the gas tank and the back of the console, and that space is reserved for the rigging tubes.  I'm feeling pretty good about this location, especially considering Nando's point on compensation and Rick's comment on bow steer .  So that's the way I'm leaning, unless someone can make a strong case for putting it in the bow.

[gran398]

That's perfect. I was worried about bow steer