Flatback Fireboat Rebuild

[CLM65]

Not bad Craig. Look very solid.  
Is it what you wanted?

Well, I did want the "solid"...but I really didn't want the messed up edges :( .  

I'm going to attempt to fix the edges.  If that doesn't work, I'll try it again from step 1.  I bought another sheet of 1/2" nidacore last week, so I have plenty of core material left.

[RickK]

Well, I did want the "solid"...but I really didn't want the messed up edges :( .  

I'm going to attempt to fix the edges.  If that doesn't work, I'll try it again from step 1.  I bought another sheet of 1/2" nidacore last week, so I have plenty of core material left.

That's how we learn. I guess the beauty of my neanderthal approach using drop cloths as a peel ply is that I knew how they were going to come out    I knew they weren't going to be pretty and would need some lovin'.  Of course I need to do the gelcoat thing backwards from your approach.  :cry:
Hey, learning is a good thing. Don't stop.

[CLM65]

Yep, definitely a learning experience.  This is my first time using gelcoat.  I'm glad I started with something small.  Hopefully I'll get better at this with the other things I'll be making.

[Callyb]

Craig, easy fix! Sand it down and add some gel to it.

They look good. I mean, you saw the disaster I had with the leaning post... Those doors are good to go.

[fishinonthebrain]

Don't beat yourself up with the alligatoring it's pretty common. Just add some thickening agent to your gel coat and apply it the sanded edge of your hatch doors. Then sand it down and you and nobody else will be able to tell.  

[CLM65]

Thanks for the encouragement, guys!  I never thought of adding a thickening agent to the gelcoat - I guess cabosil should work?

[fishinonthebrain]

Thanks for the encouragement, guys!  I never thought of adding a thickening agent to the gelcoat - I guess cabosil should work?

 

[kaptainkoz]

That's exactly what happened to me in a few spots. I thickened gel coat with West Systems 404. The difference is that it is stronger than cabosil not that this is a structural repair. Cabosil is easier to sand as well I believe. They make a 407 which is less stronger than the 404 but it is bondo red which will not work too well with white gel coat.  Point is you can thicken gel coat and fill it all in today, tomorrow or 5 years from now. That's the beauty of gel coat. So learning how to work with it now is good practice for fixing any other ding on your boat now or in the future.

[CLM65]

Beautiful weather today, so I put the doors on hold and worked some on the boat.  I managed to finish with the fuel tank.  I mounted 3/8" neoprene strips for the bottom, and 1/4" strips for the sides.  I read somewhere online that the rubber should have a minimum Shore A durometer hardness of 40, which is what I went with.  I used contact cement to attach the strips, and I also countersank a screw in each to give some positive position control.


Then I mounted 3/8" aluminum plates to the stringers.  These will give the top/tower something to mount to (there is a 1-1/4" gap beneath the plates for thru-bolting).  I had to mount these before I can foam the stringers because they are thru-bolted to the stringer tops.  Now that I have the nuts on the back side I can foam away.

[RickK]

Whoa, that's some mac-daddy aluminum  
The tank cradle looks great Craig, good idea on the screw in each pad.    What is the plan on securing it?

Coming along, coming along. (and you're right the weather was sweet today here)

[seabob4]

Beauty work Craig!  I take it you are drilling and tapping the aluminum for the t-top legs.  Yes, you could "open up the holes a bit" and drive in #14 oval heads lag screws to hold her down, they wouldn't go anywhere, but...the purists, you know...

The tank "hold down" is the easy part.  Get some 1/4" aluminum L-brackets, say 1" X 2".  Cut starboard to create spacers between the L-brackets pushed all the way into the tank recesses and the stringers, then lag the vertical of the brackets (and the starboard spacers) into the stringers.  No cross members, no aluminum straps, none of that chit.

[futch13]

Really nice   Should hold anything you want to attach!!  From the looks of the fit, you prolly won't need tank hold downs, the deck should take care of every thing  :P

[CLM65]

Thanks guys.  I haven't decided yet how I will hold it down.  There may be only about an inch of clearance between the tank and the deck at the rear end, but it is more like 4" at the forward end, so I think I need to do something.  I do like Bob's idea -clean and simple.  My other thoughts are glassing-in a triangle at each corner or glassing stand-offs on the underside of the deck.  Right now I'm leaning towards Bob's idea

[CLM65]

I take it you are drilling and tapping the aluminum for the t-top legs.  Yes, you could "open up the holes a bit" and drive in #14 oval heads lag screws to hold her down, they wouldn't go anywhere, but...the purists, you know...

The tower manufacturers I spoke to were comfortable with drilling and tapping 1/4" aluminum, so my 3/8" plates should be more than adequate, but I still plan to thru-bolt them.  I just feel more comfortable with a stainless nut on the underside of the aluminum versus the relatively soft aluminum threads.  Getting to the underside of the plate, however, is going to be the hard part.  I'm hoping the hatch for the gas tank connections will be close enough to reach them, but we will see.

[seabob4]

Craig, trust me, you'll be fine just with the bolts.  Use a Loctite product that is NOT so incredibly strong that it will make it damn near impossible to remove the bolts at a later age should you need to.

Another thing I have done many times is use 5200 as a lubricant/thread sealer.  Once the 5200 fully cures, the bolts will not loosen...