1971 Flatback

[John Jones]

Use 3M 4000UV.  5200 turns yellow in about a week.  I have some 2 year old 4000UV that is still white.  It holds just as well.

product overview
Resistant to weathering, saltwater, and stresses caused by joint movement. Seals between mechanically fastened joints on wood, fiberglass, metal and most plastics above and below the waterline. Applications include sealing deck to hull joints, thru-hull fittings, window and door frames, deck hardware, navigation lights, hatches and porthole frames. It is also paintable.

http://www.marine-products.com/boat_parts/accessories/adhesives_and_silicones/3m_adhesive_sealant_4000_uv_fast_cure_white_10oz.jsp

It comes in the "toothpaste" tubes also.  Most of the "boat" stores have it.

[LilRichard]

I can't remember if I told you guys about my idea of how I was going to reinforce my floor for the tower or not, but a quick recap: I have an aluminum "cap" that will fit over the top of the stringers where the tower will mount.  I will then place the floor over stingers and cap.  When I go to install the tower, I will drill holes into the floor and through this aluminum cap, then tap the cap for threads.

Well I had the caps fabricated, and thought I would show you some pics.  The top of the cap is 6" wide by 6' long, and overhangs off the sides of the stringers about 2" on each side.  The profile is basically the shape of the greek letter "pi".





The idea is that the tower will be bolted not only to a backing plate under the fllor, but that plate will be glued (5200) and through bolted to the stringers, thus creating a very strong junction.

More to come as they are installed.  I just wish I could TIG weld... all I have is a MIG.

 :(

[Seadog]

Amazing work LilR!

Did you have to compensate for the thickness of the 'cap', I mean, did you

have to take off a little of the top of the stringer where the 'cap' will rest

so the top of the cap is at the same level as the rest of the stringer?

The production boat guys should build their tower supports as sturdy as

yours.  Some are just screwed into the floor.

[JimCt]

Wow!  That ought to hold the tower like the Rock of Gibraltar.  With that Pi-section it will be stiff enough to distribute the load on the stringer over its entire length... and thereby avoid point stress on the stringers.  Thinking out of the box is how improvements are made.  Good job!

[RickK]

Kinda like a sliding glass door top frame - nice.  Do you have to secure it to the stringer?

[LilRichard]

Thanks guys.

The plan is that when I lay the floor down I will route a 1/4" section from the bottom of the 3/4" plywood- thus the top of this cap will be slightly recessed into the bottom of the floor.  We'll see how that works out.

Rick- yup- the plan is to secure that cap to the stringers with adhesive and a few bolts (the holes through the stringers will be sleeved with PVC so that it will not compress the stingers when torqued).

[RickK]

The plan is that when I lay the floor down I will route a 1/4" section from the bottom of the 3/4" plywood- thus the top of this cap will be slightly recessed into the bottom of the floor.  We'll see how that works out.

Any plan on how you're going to get everything lined up before routing? Maybe coat the top of the cap with something that will transfer to the wood when you lay the plywood into place and stand on it, so you have the exact outline of the cap to route out.  I'd hate to rely solely on measurements for that (plus it's easier this way). I'm sure there is something that will transfer to the resin coating on the bottom of the wood, give you the outline and be removeable.

[JimCt]

Maybe chalk the aluminum and lay the deck on it to transfer the location?  Dry erase pen will do the same thing... maybe better?

[LilRichard]

Yeah, haven't figured out yet how I will get the measurments for routing, but you guys all have good ideas.  I was thinking that the chalk method (or some sort of dye) might work well.  I am only capable of one good idea per week... I'll have to wait till next week for a solution.

[JimCt]

That's nothing... I hatch hundreds of "good ideas" each week... 99.99999% of which are unworkable and just plain ignore all laws of physics.

[LilRichard]

1) Hot as hell in FL?  Check

2) Is Rick a slacker?  Check.

3) Somehow got spray rails on?  Check.

FINALLY- after tons of fairing work... managed to get the rails permanently affixed.  Now it's rigging tube and tower supports... then the floor.  More to follow soon.



Looking at the starboard side:






So the rail was bedded in 5200 then bolted to the hull (as described in above posts).  I then covered the inside of the bolts and washers with 5200 in attempt to avoid any water entering the hull, and to keep the nuts from backing off over the 20+ years this rebuild will last!  I may chop the remaining part of the bolts off a little shorter... not that it matters that much.   <!-- s:afro: -->:afro:<!-- s:afro: -->

Not that the 'fro has anything to do with spray rails... it just looks cool.

[RickK]

Lookin' good Rick.  Progress is always a good thing. Gotta get her done before football season starts or she'll have to wait another 6 months

[LilRichard]

Actually... football saeson is when I work on it most... because it is cool out!  I would like to get the floor in before I take a break for the hottest part of the year.... we'll see if I acheive that objective.

[JimCt]

It gets hot up here for a bit in the Summer, but you guys down there must get fried.  Take it easy in the heat... heat stroke is insidious.  You'll beat me to splash-day anyway, so no heroics.

I put 5200 right up there with WD-40, PB Blaster, Visegrips, decent screwdrivers and rum.  With those in the kit, anything can be fixed, modified or put in perspective.

[LilRichard]

I agree about the potential for heatstroke... although I am typically immune to that after cycling in this heat for the past 10 years.  Rode 50 miles mainly offroad over about 3 hours on Saturday... makes working on the boat seem rather enjoyable!