Go Back   RIBnet Forums > RIB talk > RIBs & ribbing
Click Here to Login

Reply
 
Thread Tools Search this Thread
 
Old 08 November 2015, 12:51   #41
Member
 
Country: UK - England
Length: 3m +
Join Date: Sep 2008
Posts: 2,762
I'm not sure the metal work does anything but distribute the load. I'd want to look at the hull join good and hard.

While 200HP is over rated, there are two issues with over rating - handling and hull stresses. I'd hazard a guess that 200 on that rib can be a challenge to control. Hull stresses - she hasn't fallen apart since then and presumably has had an MCA survey which is a start... Was it a 200 or 2 x 100... 2 x 100 is even heavier but stresses wise may be less...? 2 x 100 would be easier to handle and makes sense for the location.

On the other issue screwed down seats are not ideal but the console is also "screwed down". The CORRECT way to fit seats with self tappers is on a bed of sikka flex. If it is sikka then its doing the work not the tappers. The tappers just hold it there while the sikka cures. If someone used some kitchen sealer (white or clear would immediately ring alarm bells vs black) that is not doing the same as sikka flex. Well sealed on sikka water penetration may not be that big an issue. Although bolted down or glassed down would be better. Can glass down now, glassing over the tappers... OR bolted for that matter if you can get a nut and washer on the inside.
__________________
ShinyShoe is offline   Reply With Quote
Old 08 November 2015, 13:38   #42
RIBnet supporter
 
jepho's Avatar
 
Country: UK - England
Town: Leighton Buzzard
Boat name: no boat yet
Make: no boat yet
Length: no boat
Engine: no boat yet
Join Date: Oct 2015
Posts: 75
Quote:
Originally Posted by ShinyShoe View Post
I'm not sure the metal work does anything but distribute the load. I'd want to look at the hull join good and hard.

While 200HP is over rated, there are two issues with over rating - handling and hull stresses. I'd hazard a guess that 200 on that rib can be a challenge to control. Hull stresses - she hasn't fallen apart since then and presumably has had an MCA survey which is a start... Was it a 200 or 2 x 100... 2 x 100 is even heavier but stresses wise may be less...? 2 x 100 would be easier to handle and makes sense for the location.

On the other issue screwed down seats are not ideal but the console is also "screwed down". The CORRECT way to fit seats with self tappers is on a bed of sikka flex. If it is sikka then its doing the work not the tappers. The tappers just hold it there while the sikka cures. If someone used some kitchen sealer (white or clear would immediately ring alarm bells vs black) that is not doing the same as sikka flex. Well sealed on sikka water penetration may not be that big an issue. Although bolted down or glassed down would be better. Can glass down now, glassing over the tappers... OR bolted for that matter if you can get a nut and washer on the inside.
The actual configuration of the previously proposed 200hp is not known to me at this time. If it was a single engine then the proposal was 70hp over the maximum recommendation by Humber. If it was a twin engine, then 90hp x 2 was the maximum recommendation. I have assumed that the manufacturer would know the design specifications, parameters and limitations of their boats better than a customer would.

The actual fixing method and quality is unknown by me at this time. Additional images will be sure to resolve that particular issue. Without any specialist knowledge and with no great general knowledge about boats, I have to be guided by what little I know, what others have advised and what my gut feeling is. The boat on offer MAY be perfectly serviceable and not give any great trouble to me as a new RIB owner. I am aware that buying into what feels to me like it could have been a less than well cared for boat, with hidden issues waiting to reveal themselves, is not a sensible course of action.

The nub of the issue for me is the willingness to override the manufacturer's recommended power maximum by altering the design from standard. Unless the owner was a qualified marine engineer, I don't have that much faith in the project as it was conceived. Everything else flows from that... I agree that if the seats were properly fixed, the issue would be negligible, other than if there was water present where it was not expected. I don't want a boat with a history of almost certainly bodged ownership behind it.

The facts speak for themselves... it is yellow, it quacks and waddles like a duck.
__________________
jepho is offline   Reply With Quote
Old 08 November 2015, 14:35   #43
Member
 
Join Date: Jun 2010
Posts: 2,934
it sounds like you have made some progress as to whether to bother with this one.

i suspect this RIB used to be a dive boat and there used to be a rack behind that single seat. that would probably explain the huge engine on a small boat. with that much power on that size of boat it must have been capable of in excess of 60mph.......i wouldn't be on it!

the seats only being screwed down is pretty poor TBH given the extent of the refit done, fixable though if you are still of a mind to buy this one. as mentioned above, it is not uncommon to screw them down then glass over the screws internally. infact, some boats only screw them down with Sikaflex, it is strong stuff! however, if it is only sika'd to the deck flowcoat then that is the weak point perhaps. with that said, if i was doing that amount of a refurb and spending 4-5k on tubes, 9k ish on engine and maybe a grand in new seating i would glass them in for sure. just seems pointless to do it up to skimp a little on that part to me....but to each their own!

the age of the hull isn't really too much of a concern if it has been looked after TBH. Obviously only you can decide if it is a problem to you given what you know now.

one thing, the seller seems to have been remarkably honest with you and kudos to them for it.
__________________
Xk59D is offline   Reply With Quote
Old 08 November 2015, 15:12   #44
Member
 
Country: UK - Scotland
Make: Destroyer 5.5/Ring18
Length: 3m +
Engine: Yam 90HP/Yam200HP
Join Date: Jul 2009
Posts: 963
That age of 5.8m destroyer was actually rated to 150HP, although it would have been based on 2 stroke weights.
Now a 150HP and a 200 HP 2 stroke weigh much the same.
__________________
69cmw is offline   Reply With Quote
Old 08 November 2015, 16:52   #45
Member
 
Country: UK - England
Town: Retford
Boat name: Spy-sea-one
Make: Excel 435
Length: 4m +
Engine: Suzuki Outboard/25/4
Join Date: Oct 2011
Posts: 7,454
RIBase
Quote:
Originally Posted by jepho View Post
Yes, thanks Xk59D. I have noted that boat as a possible one on my list previously. I did do my powerboat 2 course with JBT and they have a dry stack facility too. Seemed like a helpful group of people to me. The 3 months warranty would be useful, if one could use the boat during that time.

I suspect that the worsening weather may play a part in limiting that usage from now on. I have a tiny insight concerning their particular stretch of the Solent after the powerboat 2 course. Boats at that end of my budget might restrict me when paying for a dry stack for the whole year. hmmm... I wonder what sort of discount one could achieve by not buying the trailer. I will give them a ring during the coming week. Of course the option to wait and squirrel away a few more squid is also a possibility.
Jello

If you do look at the ribquest make sure it's a Dave rose built boat as the previous owners had some build problems 2007 - 2008 will be ok that's the same boat as I have just sold same engine very good boat.

Cheers
__________________
jeffstevens763@g is offline   Reply With Quote
Old 08 November 2015, 17:59   #46
RIBnet supporter
 
jepho's Avatar
 
Country: UK - England
Town: Leighton Buzzard
Boat name: no boat yet
Make: no boat yet
Length: no boat
Engine: no boat yet
Join Date: Oct 2015
Posts: 75
Quote:
Originally Posted by 69cmw View Post
That age of 5.8m destroyer was actually rated to 150HP, although it would have been based on 2 stroke weights.
Now a 150HP and a 200 HP 2 stroke weigh much the same.
I see. The weight is not the only issue with exceeding the recommended specification by some 25% if we take the 150hp figure. The power output and the resulting forces generated must play a part in the design of a sea-going vessel. I don't have any idea about what sort of safety margin the designers will build into their respective designs. I do know that when you a need some safety margin designed into any activity, the more you have then generally speaking, the safer you are in the event of a failure be it minor or catastrophic.

While I am reasonably sure that it would not mean instant death were a fitted engine to exceed the designer's intentions for maximum power output. The use of a machine beyond its tested design parameters may place the boat under strains and stresses that the designers have not specifically controlled.

It may well be that the boat concerned operates faultlessly for 999 times out of 1000. When the boat is stressed repeatedly in a manner which is uncontrolled by the design limitations, it will fail in unpredictable ways. I would not want any of my family or friends on that sort of boat. Keeping within the specifications may not actively save lives per se but it is unlikely to endanger them.

I am not trying to be censorious here. If a person wants to exceed the recommendations for the type of power plant they use, I don't particularly care. I would be happy to accept a ride aboard such a machine if it were just me deciding for me. I would not expose my family or friends to risks which they neither requested nor understand. I feel that usage specifications which are laid down by manufacturers of machinery are probably universally good guidelines to follow.
__________________
jepho is offline   Reply With Quote
Old 08 November 2015, 18:01   #47
RIBnet supporter
 
jepho's Avatar
 
Country: UK - England
Town: Leighton Buzzard
Boat name: no boat yet
Make: no boat yet
Length: no boat
Engine: no boat yet
Join Date: Oct 2015
Posts: 75
Quote:
Originally Posted by jeffstevens763@g View Post
Jello

If you do look at the ribquest make sure it's a Dave rose built boat as the previous owners had some build problems 2007 - 2008 will be ok that's the same boat as I have just sold same engine very good boat.

Cheers
OK Jeff, thanks for the helpful information.
__________________
jepho is offline   Reply With Quote
Old 08 November 2015, 19:53   #48
RIBnet supporter
 
jepho's Avatar
 
Country: UK - England
Town: Leighton Buzzard
Boat name: no boat yet
Make: no boat yet
Length: no boat
Engine: no boat yet
Join Date: Oct 2015
Posts: 75
Quote:
Originally Posted by Xk59D View Post
it sounds like you have made some progress as to whether to bother with this one.

i suspect this RIB used to be a dive boat and there used to be a rack behind that single seat. that would probably explain the huge engine on a small boat. with that much power on that size of boat it must have been capable of in excess of 60mph.......i wouldn't be on it!

the seats only being screwed down is pretty poor TBH given the extent of the refit done, fixable though if you are still of a mind to buy this one. as mentioned above, it is not uncommon to screw them down then glass over the screws internally. infact, some boats only screw them down with Sikaflex, it is strong stuff! however, if it is only sika'd to the deck flowcoat then that is the weak point perhaps. with that said, if i was doing that amount of a refurb and spending 4-5k on tubes, 9k ish on engine and maybe a grand in new seating i would glass them in for sure. just seems pointless to do it up to skimp a little on that part to me....but to each their own!

the age of the hull isn't really too much of a concern if it has been looked after TBH. Obviously only you can decide if it is a problem to you given what you know now.

one thing, the seller seems to have been remarkably honest with you and kudos to them for it.
Yes, I think this boat requires more attention than I could cope with given my meagre marine skills. The size of the engine and the sparse fittings before the addition of the later seating would suggest that you are right about the previous use. The phrase "spoiling the ship for a ha'porth of tar" comes to mind.

I suspect that only good pictures (hopefully in my possession soon) and being convinced by the RIBnet membership that it was not a poor purchase; are likely to sway me towards buying this boat. Thank you kindly for all of the good advice thus far.
__________________
jepho is offline   Reply With Quote
Old 10 November 2015, 22:57   #49
RIBnet supporter
 
jepho's Avatar
 
Country: UK - England
Town: Leighton Buzzard
Boat name: no boat yet
Make: no boat yet
Length: no boat
Engine: no boat yet
Join Date: Oct 2015
Posts: 75
pix of transom and seat inner

I have received two quite poor quality images of the seat inner and the transom inside. The seat shows a lot of screws and not much else. Their is no sealing in evidence as far as I can tell. I have requested an image of the outside fixing method for this additional seat.

My mark I eyeball detects that the screws are PZ roundhead screws with a variance of distance between and visibly different head angles. I suspect that pilot holes were not pre-drilled and screw centres were not measured and marked.

With the benefit of the larger image than can be posted I can also see cracked material round the 5th screw on the right (from the bottom up) and worryingly, there is a crack on its opposite number running along the material for a short distance. Approximately level with the two lower visible bolts is a line (tide mark/scum line) running around the inner container which appears as if the item was filled with water at some point. The dirt around the screw heads suggests that liquid may have been sloshing around in this compartment.

The transom image is only taken on the inside so detail and context are missing. I have requested another image of the outer aspect of the transom. I have no idea about the inherent strength of a transom but to my mind, the transom plate as fitted looks like a bodge.

With the benefit of the larger image, I can see each of the visible bolts (3 out of 4) is over torqued. There is a depression surrounding each washer and the metal is very clearly pushed in. Small washers and the use of too much force have contributed to this classic piece of butchery. The top right bolt hole appears to have been drilled in the wrong position as it is visible under the edge of the washer.

The top left bolt hole (under the red cable) appears to have the washer sunken into the metal plate. There is a distinct dark ring surrounding the washer that appears to be sunken to some degree. The other bolts exhibit this tendency to a lesser degree. The metal thickness is a detail I cannot comment on from this poor image. I suspect the main plate may be as thick as 14 gauge and it may well be some form of stainless steel. (aluminium would suffer from electrolysis in salt water)

The main plate disports a couple of subsidiary 'ears' which look to be about 16 or 18 gauge material. They support the jury rigged poles that are badly welded and held on with a couple of bolts penetrating the hull and secured with two Nylock type locking nuts. The poles extend to the hull superstructure (not sure what piece) and another piece of home brew fabrication. At the bottom of the main plate is a line showing a three small pits along its length which appear to have some sort of rust on them.

The quality which can be discerned from these two shaky images is not inspiring me to make the trip to Fife. I suspect that the enthusiast who modified the boat had abandoned the project because it could not work. I also suspect that the damage to the transom caused by using small diameter bolts and washers and then compressing two poorly welded bits of metal around the transom may have wrought far more damage than I want to take on at any price.

This boat
I will keep looking.

All comments are welcome.
Attached Thumbnails
Click image for larger version

Name:	seat inner.jpg
Views:	147
Size:	251.3 KB
ID:	109679   Click image for larger version

Name:	transom inner.jpg
Views:	209
Size:	288.6 KB
ID:	109680  
__________________
jepho is offline   Reply With Quote
Old 10 November 2015, 23:58   #50
Member
 
Join Date: Jun 2010
Posts: 2,934
Fairly serious transom work there. None of that should be there. Difficultly will be knowing what in under it of course.

The seats could be just moisture build up, happens all the time as usually something wet in storage, ropes etc.

I assume there is sikaflex under the seat, be silly not to. If you don't want to touch the outside of the seat they ideally should have cut out the inside, left a lip for screws and glassed inside to the bare deck. You could still do that of course at a later date.
__________________
Xk59D is offline   Reply With Quote
Old 11 November 2015, 06:32   #51
Member
 
Country: UK - Scotland
Town: Huntly
Make: Searider 4.7
Length: 4m +
Engine: 75 Suzuki
Join Date: Oct 2004
Posts: 186
Forget it you have spent so much time convincing yourself you will not be happy with it.

Lots of boats closer you can go and look at. Having driven from Aberdeen to south Wales once I wouldn't do it again
how about this Tohatsu 6.6m for sale, 6.60m (21'8"), 2001 | Boatshed
Hull a good reputation few people on here had them and the engines are good, cheaper and closer to you. cheeky offer, and you can always fit a bigger engine as you gain confidence.

The Humber yes really beefed up transom looks like a good job. But not for you.
__________________
ALANT is offline   Reply With Quote
Old 11 November 2015, 06:50   #52
RIBnet supporter
 
jepho's Avatar
 
Country: UK - England
Town: Leighton Buzzard
Boat name: no boat yet
Make: no boat yet
Length: no boat
Engine: no boat yet
Join Date: Oct 2015
Posts: 75
Quote:
Originally Posted by Xk59D View Post
Fairly serious transom work there. None of that should be there. Difficultly will be knowing what in under it of course.

The seats could be just moisture build up, happens all the time as usually something wet in storage, ropes etc.

I assume there is sikaflex under the seat, be silly not to. If you don't want to touch the outside of the seat they ideally should have cut out the inside, left a lip for screws and glassed inside to the bare deck. You could still do that of course at a later date.
Agreed. My thoughts (based upon nothing else but the very poorly applied metal plate and supporting pole structure) are that the transom has been damaged beyond repair. If one was supporting/strengthening the transom, the poles should not have been necessary in any event. Fitting an engine with more power than the recommendations suggest may have persuaded a person, lacking any mechanical understanding, to apply the wrong solution to a problem that should never have arisen.

The rather poor workmanship displayed is strongly suggestive that the individual responsible for the modification had no absolutely mechanical sympathy with the boat or the techniques they employed. The transom and poor workmanship are the deal breaker for me. The seat image does not give too much away but I would expect to see a much better quality of work than is evident.

My rationale is this: Failure of any part of a boat while out to sea could easily imperil the crew. It could provide an unnecessary additional stress in what may already be a stressful circumstance; like a heavy sea. Human performance is affected by many things but starting off with everything shipshape is likely to have a positive effect on frame of mind. Catastrophic happenstance is usually a chain of several small events; which link together to create the ideal conditions for the disaster which they presage.

Thank you for taking the time to look at this potential purchase and for your sound advice.
__________________
jepho is offline   Reply With Quote
Old 11 November 2015, 07:05   #53
RIBnet supporter
 
jepho's Avatar
 
Country: UK - England
Town: Leighton Buzzard
Boat name: no boat yet
Make: no boat yet
Length: no boat
Engine: no boat yet
Join Date: Oct 2015
Posts: 75
Quote:
Originally Posted by ALANT View Post
Forget it you have spent so much time convincing yourself you will not be happy with it.

Lots of boats closer you can go and look at. Having driven from Aberdeen to south Wales once I wouldn't do it again
how about this Tohatsu 6.6m for sale, 6.60m (21'8"), 2001 | Boatshed
Hull a good reputation few people on here had them and the engines are good, cheaper and closer to you. cheeky offer, and you can always fit a bigger engine as you gain confidence.

The Humber yes really beefed up transom looks like a good job. But not for you.
I take your point about being happy but I am using RIBnet to have the discussion that I would have if I was a member of a boating club and had access to people who know what they are talking about as far as RIBs are concerned. Being an absolute novice, I am having to use my own knowledge of mechanical engineering and the expertise of the RIBnet membership to assist me making sensible decisions. Until I saw the last images I posted, I was still in a position to buy the boat. I am not afraid of a little work either but the plot looks too far gone for my lack of marine knowhow and looks like a potential money sinkhole.

I can do much better. Thank you for your link to the Tohatsu. I will consider it along with a couple of other boats that I now have in the frame. Being able to discuss a boat and my needs has been incredibly useful. From your own position of knowledge it may look as if I am undecided, but I am considering everything so that I do not make an uneccesarily expensive mistake for my skill level. I have not rejected some sort of turnkey solution out of hand.
__________________
jepho is offline   Reply With Quote
Old 11 November 2015, 16:13   #54
Member
 
Last Tango's Avatar
 
Country: UK - Scotland
Town: Denny
Boat name: Highland Bluewater
Length: 6m +
Join Date: Mar 2013
Posts: 1,647
Quote:
Originally Posted by ALANT View Post
how about this Tohatsu 6.6m for sale, 6.60m (21'8"), 2001 | Boatshed
Hull a good reputation few people on here had them and the engines are good, cheaper and closer to you. cheeky offer, and you can always fit a bigger engine as you gain confidence.
I'm not advocating that this is underpowered, it'll do fine for what jepho,s looking for, but 38 knots in a 6.6mtr boat with a 90hp sounds a tad optimistic
__________________
Last Tango is offline   Reply With Quote
Old 11 November 2015, 17:17   #55
Member
 
Country: UK - Scotland
Town: Huntly
Make: Searider 4.7
Length: 4m +
Engine: 75 Suzuki
Join Date: Oct 2004
Posts: 186
Quote:
Originally Posted by Last Tango View Post
I'm not advocating that this is underpowered, it'll do fine for what jepho,s looking for, but 38 knots in a 6.6mtr boat with a 90hp sounds a tad optimistic
Yes it could be a little, but why pic up on the maximum speed the fuel consumption is more optimistic

Do you think top speed is important? how often do you go at top speed? Kinda makes it irrelevant and even if you did your passengers (ie family) would soon not want to go with you.

__________________
ALANT is offline   Reply With Quote
Old 11 November 2015, 17:18   #56
Member
 
Country: UK - Scotland
Town: Huntly
Make: Searider 4.7
Length: 4m +
Engine: 75 Suzuki
Join Date: Oct 2004
Posts: 186
Ok PICK before someone picks up on the mistake
__________________
ALANT is offline   Reply With Quote
Old 11 November 2015, 17:21   #57
Member
 
Country: UK - Scotland
Make: Destroyer 5.5/Ring18
Length: 3m +
Engine: Yam 90HP/Yam200HP
Join Date: Jul 2009
Posts: 963
I thought once you saw pictures of the metal contraption on the transom you wouldn't be making the 14hr return journey.
When I saw that rib moored in the harbour I thought "pile of pi5h" 👎
__________________
69cmw is offline   Reply With Quote
Old 11 November 2015, 17:47   #58
Member
 
Last Tango's Avatar
 
Country: UK - Scotland
Town: Denny
Boat name: Highland Bluewater
Length: 6m +
Join Date: Mar 2013
Posts: 1,647
Quote:
Originally Posted by ALANT View Post
Yes it could be a little, but why pic up on the maximum speed the fuel consumption is more optimistic

Do you think top speed is important? how often do you go at top speed? Kinda makes it irrelevant and even if you did your passengers (ie family) would soon not want to go with you.

No I don't think top speed is important, so long as there's enough "headroom" that you don't need full throttle to maintain a reasonable cruising speed and I don't think this will be an issue with the boat
Just feel that this detail of the advert is maybe a little misleading
__________________
Last Tango is offline   Reply With Quote
Old 11 November 2015, 18:16   #59
Member
 
Country: UK - Scotland
Town: Huntly
Make: Searider 4.7
Length: 4m +
Engine: 75 Suzuki
Join Date: Oct 2004
Posts: 186
Yes like the 10 litres an hour, lets all buy 90 tahatsuuuus running costs about a 3rd of other make 90hp
__________________
ALANT is offline   Reply With Quote
Old 11 November 2015, 18:28   #60
Member
 
Country: UK - Scotland
Town: Huntly
Make: Searider 4.7
Length: 4m +
Engine: 75 Suzuki
Join Date: Oct 2004
Posts: 186
Over powered?

Tornado - 5.5 RIBs and Inflatable Boats for sale in Devon, South West | Boats and Outboards
__________________
ALANT is offline   Reply With Quote
Reply

Tags
rib


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




All times are GMT. The time now is 16:38.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.