Reply
 
Thread Tools Search this Thread
 
Old 08 May 2013, 22:39   #1
Member
 
Country: Canada
Town: van
Length: 4m +
Join Date: Mar 2013
Posts: 11
RIB transom stress fractures - cause for concern?

I noticed the other day I have some hair line stress fractures on
either side of the outboard. My AB rib is only rated for 75hp but
currently has 90hp. Should I be concerned at this stage? Or is this
quite common and just something I should keep an eye on but not
worry about much? Do you guys suggest I gel coat over the cracks
to prevent water getting inside?

Any suggestions or advice is appreciated.
Attached Thumbnails
Click image for larger version

Name:	img11.jpg
Views:	208
Size:	31.1 KB
ID:	79768   Click image for larger version

Name:	image (11).png
Views:	219
Size:	286.4 KB
ID:	79769   Click image for larger version

Name:	image (22).png
Views:	194
Size:	279.3 KB
ID:	79770  
__________________

__________________
ddd333 is offline   Reply With Quote
Old 09 May 2013, 02:36   #2
Member
 
henryfreston's Avatar
 
Country: UK - England
Town: Thornbury
Make: Avon Searider 4m
Length: 4m +
Engine: 50hp tohatsu tldi
Join Date: Sep 2012
Posts: 648
I would be concerned. Considering you are 15hp over the max allowance and it is a 4 stroke. The transom is obviously under too much strain.
__________________

__________________
henryfreston is offline   Reply With Quote
Old 09 May 2013, 03:24   #3
RIBnet admin team
 
Poly's Avatar
 
Country: UK - Scotland
Boat name: imposter
Make: FunYak
Length: 3m +
Engine: Tohatsu 30HP
MMSI: 235089819
Join Date: Sep 2005
Posts: 11,019
much has been discussed on transom cracks in the past. Those look like proper cracks rather than suface crazing (there is some of that too). In which case they need repairing properly: grind our old gel, make sure material underneath is sound and dry. Consider reinforcing. Repair gel.

Unless you do something to beef it up / reduce load then it will happen again with the new gel.
__________________
Poly is offline   Reply With Quote
Old 09 May 2013, 03:30   #4
Member
 
Country: UK - England
Town: Hamble
Length: 9m +
Join Date: Dec 2002
Posts: 2,317
Quote:
Originally Posted by henryfreston View Post
I would be concerned. Considering you are 15hp over the max allowance and it is a 4 stroke. The transom is obviously under too much strain.
lol, so it's a bit like a sell by date on a packet of sausages, eat by the 27th coz on the 28th they'll poison you!

the transom requirements for a 75, 90 or even a 200 hp motor are the same, if it's showing signs of letting go, it's because it wasn't built that well, not because it has a slightly bigger motor than it's rated for.
__________________
It is better to remain silent and be thought a fool, than to speak and remove all doubt!
Dirk Diggler is offline   Reply With Quote
Old 09 May 2013, 03:38   #5
Member
 
Country: UK - England
Town: Bristol
Make: Ribcraft
Length: 5m +
Engine: Yamaha
Join Date: May 2006
Posts: 4,272
I wouldnt be happy with that , as the boys say, get it looked at cos it aint right! Send me ya engine and will give you £2000 for it !!
__________________
matt h is offline   Reply With Quote
Old 09 May 2013, 03:41   #6
Member
 
Country: UK - England
Town: Sussex
Make: RIBTEC 655
Length: 6m +
Engine: Yam 150
Join Date: Oct 2007
Posts: 1,159
If you are worried then find a friendly surveyor with a thermal imaging camera - that will show up and serious concerns, on here you'll just get opinions as no one can really see whats under the gel.
__________________
thomas is offline   Reply With Quote
Old 09 May 2013, 04:26   #7
RIBnet Supporter
 
willk's Avatar
 
Country: Ireland
Make: Redbay Boats
Length: 9m +
Engine: 370hp
Join Date: Feb 2008
Posts: 13,809
RIBase
Quote:
Originally Posted by Dirk Diggler View Post
lol, so it's a bit like a sell by date on a packet of sausages, eat by the 27th coz on the 28th they'll poison you!
I'd REALLY enjoy listening to you explain to Mrs willk why that isn't true...

__________________
willk is offline   Reply With Quote
Old 09 May 2013, 09:24   #8
Member
 
Country: UK - England
Town: Hamble
Length: 9m +
Join Date: Dec 2002
Posts: 2,317
Quote:
Originally Posted by willk View Post
I'd REALLY enjoy listening to you explain to Mrs willk why that isn't true...

yeh, tell me about it. My wife can be a couple of hours doing the supermarket shopping, just coz she like to check sell by dates, and of course contents.
__________________
It is better to remain silent and be thought a fool, than to speak and remove all doubt!
Dirk Diggler is offline   Reply With Quote
Old 09 May 2013, 14:37   #9
Member
 
simon23's Avatar
 
Country: UK - England
Town: liverpool
Make: tohatsu6.1 one desig
Length: 6m +
Engine: mariner 125hp
Join Date: Jan 2012
Posts: 357
Is the transom designed to carry the weight of a outboard or the thrust of a outboard.if its the later you should only run at 5/6 revs and it should be fine

Sent from my GT-S5830 using Rib.net
__________________
simon23 is offline   Reply With Quote
Old 09 May 2013, 16:38   #10
Member
 
Erin's Avatar
 
Country: UK - Channel Islands
Town: A large rock
Boat name: La Frette
Make: Osprey Vipermax
Length: 6m +
Engine: 200 Suzzy
Join Date: May 2004
Posts: 2,853
Quote:
Originally Posted by thomas View Post
a thermal imaging camera - that will show up and serious concerns,
Explain please. How does cracking give a thermal signature?
Erin is offline   Reply With Quote
Old 09 May 2013, 17:04   #11
Member
 
Country: UK - England
Town: Sussex
Make: RIBTEC 655
Length: 6m +
Engine: Yam 150
Join Date: Oct 2007
Posts: 1,159
When I bought my last yacht I use a surveyor who scanned the hull with his thermal imaging camera, you could see everything, cracks, weaknesses and the makeup of the hull - have a look in the gallery section of International Yacht Surveys Hamble Southampton - Marine Yacht Inspections Surveys. and you'll see what I mean.
__________________
thomas is offline   Reply With Quote
Old 09 May 2013, 17:09   #12
Member
 
Country: UK - Wales
Town: Southampton
Boat name: DynaMoHumm/ SRV/deja
Make: Avon8.4, 5.4 & 4.777
Length: 8m +
Engine: Cat3126 Yam 90 &70
MMSI: 42
Join Date: Dec 2003
Posts: 6,559
Quote:
Originally Posted by Dirk Diggler View Post
yeh, tell me about it. My wife can be a couple of hours doing the supermarket shopping, just coz she like to check sell by dates, and of course contents.
probably gives you enough time to clear out the hot food section

hopr your'e well sir
__________________
Here it comes again, I don't stand a chance
Soul possession, Got me in a trance
Pullin' me back to you - Deja Voodoo
Rogue Wave is offline   Reply With Quote
Old 09 May 2013, 17:18   #13
Member
 
Country: Canada
Town: van
Length: 4m +
Join Date: Mar 2013
Posts: 11
Thanks for all the replies.

I think I will get some custom aluminum "L" shaped plates made up, bolt those on after some gel coat work and see how if goes.

Cheers!
__________________
ddd333 is offline   Reply With Quote
Old 09 May 2013, 17:44   #14
Member
 
Jorgos's Avatar
 
Country: Greece
Town: Pireus
Boat name: Joanna
Make: marin stiletto 737
Length: 7m +
Engine: Evinrude ETEC 250
Join Date: Jan 2009
Posts: 157
RIBase
Quote:
Originally Posted by ddd333 View Post
I noticed the other day I have some hair line stress fractures on
either side of the outboard. My AB rib is only rated for 75hp but
currently has 90hp. Should I be concerned at this stage? Or is this
quite common and just something I should keep an eye on but not
worry about much? Do you guys suggest I gel coat over the cracks
to prevent water getting inside?

Any suggestions or advice is appreciated.
I will say something different.
Sure is not the best thing.
But tis is only the top cell of your boat.
Motor normally is relying on the stern , so if you can have a good look what is happening undernith , could be that this stress is not that realy important. .

I would not worry so much if there are not any more signs of damage internally.

Usually 75 and 90 hp motors have the same weight and they are many excamples internationally tha they dont give trouble and boats are calculated for much more weight!!
__________________
Jorgos is offline   Reply With Quote
Old 09 May 2013, 17:48   #15
Member
 
mister p's Avatar
 
Country: UK - England
Town: LONDON
Make: SR4/ZODIAC/3D
Length: 4m +
Engine: 30T/40T
Join Date: Oct 2011
Posts: 1,433
Do you tow it with the engine down?
__________________
mister p is offline   Reply With Quote
Old 09 May 2013, 18:54   #16
Member
 
kerny's Avatar
 
Country: UK - England
Town: Ashton-under-Lyne Lancs
Boat name: IMOGEN
Make: Air-Craft 5.4
Length: 5m +
Engine: Suzuki df70a
MMSI: 235087492
Join Date: May 2010
Posts: 7,078
RIBase
Send a message via Skype™ to kerny
Quote:
Originally Posted by mister p View Post
Do you tow it with the engine down?
Naughty ,Naughty mister p
__________________
Member of S.A.B.S. (Lancashire Division)
kerny is offline   Reply With Quote
Old 09 May 2013, 22:02   #17
Member
 
Country: Canada
Town: van
Length: 4m +
Join Date: Mar 2013
Posts: 11
Quote:
Originally Posted by mister p View Post
Do you tow it with the engine down?
No, I just have it like that so it fits in the parking stall.
__________________
ddd333 is offline   Reply With Quote
Old 09 May 2013, 22:05   #18
Member
 
Country: Canada
Town: van
Length: 4m +
Join Date: Mar 2013
Posts: 11
Quote:
Originally Posted by Jorgos View Post
I will say something different.
Sure is not the best thing.
But tis is only the top cell of your boat.
Motor normally is relying on the stern , so if you can have a good look what is happening undernith , could be that this stress is not that realy important. .

I would not worry so much if there are not any more signs of damage internally.

Usually 75 and 90 hp motors have the same weight and they are many excamples internationally tha they dont give trouble and boats are calculated for much more weight!!

Thanks for your opinion, I'm tempted to gel coat over it for now and see
if it gets any worse. Its a 90HP 2 stroke which is probably about the same
weight as the 75HP 4 stroke.
__________________
ddd333 is offline   Reply With Quote
Old 10 May 2013, 03:29   #19
Member
 
boristhebold's Avatar
 
Country: UK - England
Length: 7m +
Join Date: Aug 2009
Posts: 1,543
I think you have more to worry about than the cracks, if your boat is rated for 75HP and you have 90HP and presumably you have insurance, what do you think the insurance company are going to say if you have any claims, consider worse scenario as in an injury or worse to a passenger or others, you might find you are personally paying out for the rest of your life.

As to the crack, you really need to remove the gel coat and have a look under it, it may just be gel coat cracking but it could be worse under it.
__________________
boristhebold is offline   Reply With Quote
Old 10 May 2013, 04:26   #20
Member
 
mister p's Avatar
 
Country: UK - England
Town: LONDON
Make: SR4/ZODIAC/3D
Length: 4m +
Engine: 30T/40T
Join Date: Oct 2011
Posts: 1,433
Well, if you don't tow it with the engine down that removes that as a possibility of stressing the transom incorrectly.
__________________

__________________
mister p is offline   Reply With Quote
Reply

Tags
rib

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 16:13.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×