Stringer repair

[Woodonglass]

That's a bit OVERKILL IMHO but a nice job!!!

 

[bjf66]

No Title

Up early this morning,into garage, putting down the remaining 2 layers on 2nd stringer
- #3 layer: 2oz CSM
- #4 layer: 25oz biaxial fabric
- total now 42oz on stringers
- added some strength between inner-outer stringer while I was there
- need to figure out what Im going to do in centre have purchased 15x40mm hardwood and was going to glass that in down the centre of boat
Need to get the surface drive down low in hull
may run 2 drain plugs either side of the surface drive

off for 2 weeks then will start building lower transom up to approx. 8 degrees angle on outside, getting ready to locate surface drive
still need to finish cutting out ballast tank up front

 

[bjf66]

No Title

Needs some advise on what to do for the centre where I have removed the previous stringer
1. place some strip of hardwood there 40x20mm and glass in...this was original plan?

2. lay some fibreglass fabric to blend into the floor?

3. Other options?

 

[Baylinerchuck]

Are you questioning whether or not the center stringer is necessary?

 

[Woodonglass]

Put it back the way it was!!!

 

[bjf66]

Yes need to know whether should put a trimmed down version of the centre stringer back in boat, or do away without it

previous set up was outboard, now having surface drive and inboard needs more room required inside 2 inner stringers
as per photos

 

[Baylinerchuck]

I would put down a trimmed down stringer if it were me. A stringer was in there for a reason, and putting one back gets it pretty close to the same design. A cut down stringer is stronger than none IMO.

 

[bjf66]

Retuned today from overseas trip
Looking forward to getting back into fibreglassing

Originally the boat was setup with 250-300hp outboard
I'm assuming this is reason for the centre stringer which was approx 160x50mm
I need to reduce the height at least 100mm to 50mm
Also want to get 12 Litre engine sump low in boat
There are 4 orgervstringers in boat
I'm not sure what size the 2 outer stringers are but at guess they would be 100mm H
I was thinking of laminating 2 * 40x25 mm together to end up with 40x50 mm and lay
- 2oz CSM
- 25oz biaxle

Anyone had experience removing the centre stringer if converting from outboard to inboard ???

 

[bjf66]

No Title

Dear All
Need to make up a wedge in between surface drive and transom, as need to get the surface drop to bolt onto transom at 12 degrees
Therefore lower transom now 2 degrees, needs to be 12 degrees
the disc would be 200mm Dia tapering from top of 20mm down to 2mm over the 200mm Dia, or make the wedge disc slightly larger
The wedge would then need have inside approx. 100mm cut out with hole saw, 4 bolt holes
The wedge is not taking any stress as the surface drive load is bolted through transom just needs to be take the sandwished bolted pressure
1. add strips of fibreglass CSM, 25 oz biaxle to build up the thickness over the width of the lower transom which is 500mm wide, would need to be 20mm thick at lowest part
2. attempt to fll and shape with PB, however concerned with trying to fill gap 20mm thick
3. have machine shop machine up a aluminium wedge...note have the aluminium, cost approx. $300 to machine
4. make the wedge using Laminating casting epoxy west 105, as I have spare 3 litres, this would be epoxied onto Vyinyl ester transom, then corners filleted
5. Option 3 using Vinyl Ester, CS 6mm fibres, microspheres
Was thinking could cast the resin into a large plastic lid, angle the lid to achieve the desired basic shape and degree wedge, then drill out holes cut inside out
attached picture this is represented of the gap which need sot be filled
sorry picture is on angle, top is left hand side
cheers
Brett

 

[Scott Danforth]

option 4, a chunk of white oak cut into a wedge and glassed into place, then faired

 

[bjf66]

scott
thank's for comments I managed to find someone who would sell me a offcut of Vic Ash (Mountain Ash) without purchasing 4.3 metre length
we will give this a go
seems the hardwood will be easier to work with in routering out the 4" hole for the surface drive nose to come through
managed to pick up the 1/2" UNC x 1000mm long rod to make up the 4 extended mounting bolts

 

[Scott Danforth]

May want to make the extended bolts from aquamet 22 or 17-4ph shaft

 

[bjf66]

Scott

Thats a good point
There is plenty of 304/316 stainless rod locally, had a quick look at the the 17-4 PH which has approx. twice the mechanical strength as 304, however might struggle to get this in the threaded rod in Australia,

where would you source this in USA?

 

[Scott Danforth]

I would make it. We have both 17-4ph and Aquamet 22 (propeller shaft) in stock

 

[bjf66]

scott

what would the cost be for 4 x 200mm long 1/2" UNC threaded rods?
cheers
Brett

 

[Scott Danforth]

thru our shop - way too much. Shop rate is $100 per hour. plus you would be looking at a long lead time

check around, plenty of boat builders in Australia. you should be able to find propeller shafting (Aquamet)

would be much cheaper and faster buying from companies that specialize in fasteners here are a few

these are in Australia:

http://www.anzor.com.au/duplex-monel-titanium/super-duplex-2507-uns-s32750-fasteners/product

http://www.revolutionmaterials.com.au/fasteners.php

here are some more

http://extreme-bolt.com/17-4-ph-threaded-rod.html

http://www.ameribolt.com/17-4-PH-Studs-New.html

http://www.atlrod.com/exotic-materials/17-4-ph-stainless/

https://torqbolt.com/suppliers/17-4-ph-threaded-rod/

http://www.deltafastener.com/17-4 ph.html

 

[bjf66]

Scott
thanks for the list, I had contacted one of the Aussie supplies earlier in day but they had no stock of threaded rods, although having received your list, fired emails off to 6 of them asking for quotes, whether I get reply is another thing as orders small $ for the 17-4 HP

Made up a hardwood wedge on saturday. Used the router to make the 12 degree angle, was just finishing it off, trimming outside and wedge split
Ruined my day.
Never mind decided on sunday to bite the bullet and make aluminium wedge, so will machine this from 32mm plate
I have drilled the holes, and will cut centre out and try and get someone to machine the 12 degree locally

Then not to sure whether I should epoxy the aluminium wedge onto the VE fibreglass resin of just have it as loose piece sandwiched in between transom and drive
Have noted people seem to get mixed results with laminating/encapsulating aluminium in fibreglass

anyone got any thoughts here
- use epoxy to glue aluminium plate to transom
- use a 3m or other purpose glue

 

[Baylinerchuck]

What if you glued it with like 5200 or something similar, then encapsulated it in VE and glass?

 

[Scott Danforth]

I would have just glued the two pieces of wood back together with tite-bond III or other water proof wood glue

 

[bjf66]

actually the hardwood wedge ended up in 3 pieces, which pissed me off a little; have since drilled the aluminium plates 32mm, and 10mm backing plate, cut out centres, which have been able to get a maximum 10 degrees with the 32mm plate, so will glue on to transom and see whether can creep another 2 degrees when I set it up
Then encapsulate the aluminium plate
Will be taking Al. plate to machinist tomorrow to get angle cut, hopefully can get this on the transom by end of the week