Searider Autopsy Photos

jefflee2k · 19 August 2010, 00:02

Water got into the plywood around the bolt anchors and rotted out the deck. I had to cut out 2 holes, each about 2 ft sq., to get to good wood. The front flotation chamber was completely saturated. Since there was no easy way to get a reliable seal on the inner chamber, I will be closing off the flooding ports while the boats in the water.

The pictures show the inside of the 5.4 SR for anyone that might be curious about what is going on down there. The deck is have inch ply sandwiched between heavily reinforced glass on the bottom and glass with a light chopped mat on top. The bolt anchors are 2 in sq stainless. You can see a good cross section of the foward ballast chamber, as I cut it for easier access for repairs. The rear chamber is intact. The Aluminum angle in the photos is what I put in to support the new deck.

Downhilldai · 19 August 2010, 00:14

Quote:

Originally Posted by jefflee2k

You can see a good cross section of the foward ballast chamber, as I cut it for easier access for repairs. The rear chamber is intact.

They're buoyancy chambers, not ballast chambers.

ProjectAvon2010 · 19 August 2010, 01:29

Thanks for the pics. It's interesting how different the 5.4 is from the 6m. I just got done cutting the deck off, and there was a lot more material, and an actual ballast tank... which is now gone.

willk · 19 August 2010, 08:27

Quote:

Originally Posted by Downhilldai

They're buoyancy chambers, not ballast chambers.

Not any more they're not...

jefflee2k · 19 August 2010, 10:24

Your 100% correct. The whole hull, when left to flood as intended is a ballast chamber, with the smaller foam filled chambers to add buoyancy and distribute the water evenly for better handling. I try to refer to them in as many different ways as possible so that someone doing a search in the future can find them easier.

HUMBER P4VWL · 19 August 2010, 11:05

Are the insides of other ribs similar to this, humber specifically, in very simple construction terms? (Except that instead of the under deck area flooding in and out the flooding hull hole on the outside at the rear, it would drain through a drain plug inside the boat at the bottom of the rear well where a bilge is often located)

My thoughts are along the lines, obviously the deck doesn't rot as it is sealed within glass both from water above and below, so unless you screw in to it, it won't rot.

Or do ribs without the constant flooding have a much lighter/less comprehensive glass coating under the deck?

wiLlfish · 19 August 2010, 11:13

Quote:

Originally Posted by jefflee2k

Water got into the plywood around the bolt anchors and rotted out the deck.

fukk mee

didd yew saiy

'hooston, wee av a problum'

wiLf

C-NUMB · 19 August 2010, 16:38

Quote:

Originally Posted by jefflee2k

The Aluminum angle in the photos is what I put in to support the new deck.

Great pictures, very informative! Original build quality looking OK. Regarding the Aluminium angle, there is maybe one potential problem. It seams to be very close or even touching the hull(bottom). If/when structure moves in heavy weather the alu might start to work its way through the hull.

I know this is not likely to happen, but we had a GRP hard boat where we got a hole in the hull due to kind of a similar reason. Glueing/glassing the alu profile to the hull might eliminate the risk. Or then the SR is so stiff that it won't move anyway. Keep the good pictures coming on your project!

jefflee2k · 19 August 2010, 17:15

The aluminum is actually glassed to the hull. I have a T-top (permanent shade) for the boat that pulled the anchors out of the rotten deck to start this project. The aluminum will help anchor the top and distribute the load across the deck and hull. This boat was in service with the coast guard, and has a pair of lifting rings on the deck that they glassed to the hull in the same way for hoisting the boat out of the water. I also modified the shade so that it comes off while trailering, so the boat will only have to support an upward load generated by the boats top speed of 35 knts as opposed to highway speeds. I wish I didn't need the top, but we get 4 months of near 100'f weather and afternoon rains are possible most days.

C-NUMB · 19 August 2010, 18:53

Quote:

Originally Posted by jefflee2k

The aluminum is actually glassed to the hull.

Ok, then no issue. Regarding T-tops, what is the protection factor for rain? Sun or heat is not typically an issue here(except for this summer with brilliant weather) but rain is not unusual. Not many T-tops around here.

jefflee2k · 19 August 2010, 20:01

Not much when you are moving. But if you spend much time fishing, it gives you a place to duck under and wait it out. Mostly for the sun though. The reason they are popular on fishing boats, is they provide the shade of a bimini, but let you walk around the boat while fighting a fish without having to pass your rod around the supports and straps.

njensen · 20 August 2010, 14:53

Man that's nice ;-) ..... how thick is the deck... you write "inch", so 25mm plywood + grp

I asked Avon for the dimensions and layout of the deck (SR 4.7) 10 years ago. they didn't want to tell. I considered to cut a hole and put in a fuel tank, but never did it.

Now many years later i finally kickstarted the project. However i didn't dare to cut the holes in the deck so i mounted the 62 L fuel tank topside.

I grinded of the fibre glass on the deck and milled some slots as well. I made a mounting plate with custom designed brackets for attaching the fuel tank and my new steering console. The mounting plate is clued on to the deck with expoxy and high density filler.

The frontpart of the steering console is reused from the original, the rearpart is made from scratch this spring.

It would have been nice to get the fueltank lowered into the deck, since it would leave some design flexibility for the seating part, i.e. hight/width ect..

However my solution works quite fine, and i spend 100+ hours on it, so i think i'll stick to it the next couple of years...

Downhilldai · 20 August 2010, 15:07

What max speed do you get from the SR4.7 with the DT65?

ProjectAvon2010 · 21 August 2010, 02:58

..... how thick is the deck... you write "inch", so 25mm plywood + grp

I asked Avon for the dimensions and layout of the deck (SR 4.7) 10 years ago. they didn't want to tell. I considered to cut a hole and put in a fuel tank, but never did it.

...

I just cut through the deck of my 6m, and it was .5" thick, fully encased in 1708 like fiberglass, which added about 1/16" to top and bottom. Where the deck met up with a stringer, the wood was doubled up. Despite what seemed to be a thorough glass job, still did not prevent the stringers from rotting out in the stern. I'm glad I got into ripping the deck and stringers out, in total, as I would have to come back and do it again later.

The link below is my project website. I've added some recent pictures of the deck project (mostly out), and some example of the rot...

http://gallery.me.com/milton.leimkuehlers#100148

jefflee2k · 21 August 2010, 05:57

Sorry. That was a type-o. The deck is 1/2" ply with about 1/8" grp on bottom and 1/16" on top. I was really hoping to utilize some of the under deck space for storage, but there is just not that much room down there. By the time I was finished glassing in new supports for the deck there wasn't much left at all. You could fit a collapsable bladder type fuel tank or custom fit one along the keel, but not much else.

Avon2010,
Are those before and after pictures? Or is the gray Avon a new boat for comparison purposes? Either way I really like the anchor locker ans samson post.

njensen · 22 August 2010, 14:24

Quote:

Originally Posted by Downhilldai

What max speed do you get from the SR4.7 with the DT65?

I have done 36 knots... but with my current prop it's more like 32. I need the power at low speed to get planing (diving, waterskiing ect.)

Downhilldai · 22 August 2010, 18:44

What's on there now? 13" pitch?

ProjectAvon2010 · 22 August 2010, 19:26

Avon2010,
Are those before and after pictures? Or is the gray Avon a new boat for comparison purposes? Either way I really like the anchor locker ans samson post. [/QUOTE]

The orange boat are current pictures (ongoing), The gray ones mixed in there are a ribcraft from a Boston company that runs corporate outings to the Boston Harbor Islands. I take a lot of pictures to get ideas for when I'm putting my boat back together.

I have plenty of room below deck for a fuel tank, but I had to take all the stringers out. I completed the "gut" last night, and I was surprised about how rotted the wood was.

I'm replacing the stringers with closed cell foam wrapped with Prisma (check out Jamestown Distributors) cloth. Just need to get rid of all the wood....

jefflee2k · 23 August 2010, 03:51

I finished glassing in the patches. When I tried to paint the deck, I went with the same primer I used to paint the deck last time "Bullseye 123 plus". After 12 hours, it was still wet. I was able to wipe it off with old newspaper. The guys at the paint store recommended a 2 part epoxy paint. Actually, it is a garage floor finish. It looks great, but only comes in grey, and epoxy will yellow and get brittle when exposed to UV. I can either top coat with a clear sealer or come back with a matching orange paint.

ProjectAvon2010 · 25 August 2010, 01:51

Jefflee,

I've had good luck with Interlux before, but I had to use the epoxy primer over the polyester resin that was currently on the boat. I think it was called Interlux brightside. I brushed it on, and it was self leveling. Good stuff.