welds cracking STABI-CRAFT

[stinky-stabi]

68195681966819768198
few pictures that i took but there was a lot more that i didnt have my camera for when fabricator had the floor up....those welds are on the sealed(not sealed anymore) pontoons...v crack is weld pulled through floor letting water in,an the long crack is the floor connenting to the hull... its going back to get more welding fixed up today...but in my opinion this sort of thing shouldnt be happening in 287hrs no matter how its been treated.....>:(

[Salad Fingers]

wow werid to see that crack going at right angles to the weld in Pic #2. Doesn't happen very often.
Not very good at all, I had my 12month old stacer start cracking up like that and sinking but you wouldn't expect that with a stabi?

[Moonlighter]

One thing to consider is the trailer and it's set-up.

Not having a go at you at all, its just that it is regularly reported in boating magazines that more damage to hulls is caused by incorrectly setup trailers, or boats not tied down hard onto trailers when being towed (especially over rogh roads), than is ever caused by using boats in even the roughest conditions.

Is there any way the damage your boat has suffered could be related to such causes? Did the dealer supply/set up the trailer that's under the boat?

Regards

ML

[stinky-stabi]

One thing to consider is the trailer and it's set-up.

Not having a go at you at all, its just that it is regularly reported in boating magazines that more damage to hulls is caused by incorrectly setup trailers, or boats not tied down hard onto trailers when being towed (especially over rogh roads), than is ever caused by using boats in even the roughest conditions.

Is there any way the damage your boat has suffered could be related to such causes? Did the dealer supply/set up the trailer that's under the boat?

Regards

ML
have allready gone down this road with the fabricator(boat builder) and he seems to think that the material (ally sheetz) are chinese or the workmanship is just shite(i got the monday boat). just picked it back up this sarv and the fella workn on it said it is all very strange as welds are splitting in all directions????..............::)

[TheRealAndy]

I am by no means an expert in this subject, but I do recall some stuff from uni and that is not a weld failure. Looks like a design flaw. Aluminium is pretty flexible and that looks like failure due to the material either being to brittle or no room to flex due to poor design. I would be making some calls to stabicraft, warantee or not and asking questions. Rewelding failures like that is only a short term solution.

[stinky-stabi]

I am by no means an expert in this subject, but I do recall some stuff from uni and that is not a weld failure. Looks like a design flaw. Aluminium is pretty flexible and that looks like failure due to the material either being to brittle or no room to flex due to poor design. I would be making some calls to stabicraft, warantee or not and asking questions. Rewelding failures like that is only a short term solution.

yes have spoken sean who is the australasian sales manager this morning , (i rang nz this morning)am awaiting for some one from the factory to call back. the people who have fixed have advised to get a pro(inspection) on to it as he states there is more to it than meets the eye lolol as you say a short term fix

[boatie_72]

I agree to the other post, it doesn’t look like it’s a welding problem as such, more a material issue i.e. too hard on the scale. Aluminium has a 10% tolerance on its softness/hardness, which means its either 10% softer or 10% harder. And you don’t know what you’re going to get from batch to batch unless you have the tool to check it yourself. As for the material coming from china, a hell of a lot of the aluminium comes from china, even one of the best mills garmco get material made in china.

[unchainedjenner]

hope something gets sorted out for you there mate.

[Spaniard_King]

Yeh looks like material failure to me. Weld failures usually follow the weld direction either along or in the weld.

[TheRealAndy]

Once again, testing my memory here but I am certain we used portable brinell testers at uni for checking material hardness. Might pay to encourage stabicraft to use one. Might also help if you tell them about this thread, and how eager we are to see a good outcome!

[TheRealAndy]

Just had a though. The guys who machine aluminium engine heads for cars usually have those portable hardness testers. These guys are also pretty clued up on materials. Might pay to swing by one of them with a 6 pack and ask them to test the boat in a couple of spots.

[stinky-stabi]

Don
#
I have spoken to Owen (our in house warranty Manager).# The process going forward from here would be for you to go to your nearest Stabicraft dealer and they would fill in a warranty claim form.# At which stage we will assess the information received from them and Owen will respond with our reply/course of action.
#
If you are to get these issues fixed else where we are unable to stand behind this as warranty sorry.

[johncar]

You may have covered it somewhere else here so please excuse me if I missed it but did you take this issue to Stabicraft when you first started having problems?
I would assume that would have been your first port of call and hopefully you did. If you did not then I would ask why not?
I could understand to some degree that they would be less interested if major work had already been done on the boat before they got to see it, although if the minor weld repairs were a small part of an obvious major problem throughout the boat then they should help you regardless.
I thought that these boats had a reputation of being fairly robust so I would think that they would be interested if one were cracking up under normal use.
I have found that it pays to be patient, courteous and polite when dealing with such matters no matter how upset and frustrated you may feel, be careful not to get offside with the manufacturer. If you do all the right things and at the and of the day they leave you high and dry well then you have some justification to complain if you are in the right.

I wish you good luck with it.

I saw a thread recently where a guy was complaining about his boat digging the bow in at speed and after various amounts of advice/help from members he confessed that it had previously come off the trailer at 100kph. I am sure that this is not the case with your problem but when criticising a product we don't always know the full story and history of the boat on here so I just remain open minded about such things, that's all. If others are having similar problems then I am sure it will come out on here, should be plenty of Stabi owners out there..

[06Adsy]

Don
#
I have spoken to Owen (our in house warranty Manager).# The process going forward from here would be for you to go to your nearest Stabicraft dealer and they would fill in a warranty claim form.# At which stage we will assess the information received from them and Owen will respond with our reply/course of action.
#
If you are to get these issues fixed else where we are unable to stand behind this as warranty sorry.

Seems like a reasonable response. Why did you not take it back to Stabi in the first place?

Why do you have three threads going about the same issue?

Can you explain what this pic is?
http://ausfish.com.au/vforum/attachment.php?attachmentid=68197&d=1308003115&thumb=1

Sorry for all the Q's but I'm just trying to understand a little better......

[Owen]

Based on the photo's presented I would think the cracks are as a result of flexing.
Apart from the pinhole, in one weld, they appear to be of good quality.
Plus you have cracking in areas with no weld. One appears to be at the end of a rib.. therefore a point of work hardening (the rib wont felx, but the sheet will right beside it)
Those cracks look like localised flexing caused by... Oh I don't know... Something like banging away on a roller on the other side? Strap it down pretty snugly?
Without seeing the actual setup, one can't make any conclusions, but I think Stabi is absolutely right to request it be taken to one of their dealers given what you have shown.
Note: I have no interest in Stabicraft, have never owned one, wish to own one or whatever.
I have spent a lot of years working with aluminium and that's what I base my comments on.
The fabricator who assessed it could be on the money... he's seen it after all.
But there's no way I (in Stabi's position) would pay up based on the evidence given here without seeing it myself.

[TheRealAndy]

Based on the photo's presented I would think the cracks are as a result of flexing.
Apart from the pinhole, in one weld, they appear to be of good quality.
Plus you have cracking in areas with no weld. One appears to be at the end of a rib.. therefore a point of work hardening (the rib wont felx, but the sheet will right beside it)
Those cracks look like localised flexing caused by... Oh I don't know... Something like banging away on a roller on the other side? Strap it down pretty snugly?
Without seeing the actual setup, one can't make any conclusions, but I think Stabi is absolutely right to request it be taken to one of their dealers given what you have shown.
Note: I have no interest in Stabicraft, have never owned one, wish to own one or whatever.
I have spent a lot of years working with aluminium and that's what I base my comments on.
The fabricator who assessed it could be on the money... he's seen it after all.
But there's no way I (in Stabi's position) would pay up based on the evidence given here without seeing it myself.

The reason I dont think its flexing is because fatigue failure in aluminum normally leave a sort of white powdery look. That looks like tensile failure you find in brittle materials, but then again without a close look its hard to tell. Like I said before, I am no expert on the matter. I only did a semester of material science at uni, and that was about 10 year ago now.

[Owen]

As the material did not crack when being formed, we can pretty much rule out material that was a long way outside spec
That means the cracking had to have been initiated by flexing. Metal does not crack until it's elastic limits have been exceeded

The question is was the flexing normal for the part in question... Which would mean the material hardness or quality was such that it did not fail when the ribs were formed but was not able to cope with subsequent " normal" flexing

Or

Was the material and construction the same as all the other stabis on the market that have not cracked up?
If the latter, then it is operator error
Either by manner of operation or how it was transported
May be not what the owner wants to hear, but still a possibility that the manufacturer has every right to expect to be able to check


Doing a brinnel test now most likely won't tell you much because the area will have work hardened
Besides which it is meaningless without specific reference points
I used to use 76mm tube that had to fall within a very specific brinnel range to be bendable
It could be well within mill specs and be useless to me because it would crack when bending, so every lot had to be tested
I seriously doubt any production boat manufacturer is using material that close to the edge as losses would be too high and it makes no sense from an engineering point of view on a boat.

I saw on another thread a surveyor is going to check it out.
I hope the matter is resolved to everyone's satisfaction



Cheers
Owen

Sent from my iPhone using Tapatalk

[mitchdemeanor]

Hmm some of the photo's (the one's across the welds) look like they have been caused by flexing (might be the lighting though). However the other one's I'm not at all sure about, its got me curious. I'm head fabricator at an aluminium window company and have never seen the like of that before, I will ask the rest of the guys tomorrow if they have an explaination

[charlie09]

Mate I've been welding for years. I've never seen cracks go through welds like that. As a previous post mentioned it always goes along parallel to the weld. Usually the actual weld is stronger than the surrounding material. Maybe a metallurgist may be of some use. He would be able to better tell you what's happened. I.E poor quality aluminium and or weld technique or metal fatigue from flexing.

Hope you get a satisfactory resolution to this problem.

[stinky-stabi]

thanks for all the helpful hints an facts has been a great help , I did not once say anything about wanting money or compensation I just stated the facts and the circumstances so be it , meeting surveyor after lunch today so will keep you informed

[TheRealAndy]

As the material did not crack when being formed, we can pretty much rule out material that was a long way outside spec
That means the cracking had to have been initiated by flexing. Metal does not crack until it's elastic limits have been exceeded

The question is was the flexing normal for the part in question... Which would mean the material hardness or quality was such that it did not fail when the ribs were formed but was not able to cope with subsequent " normal" flexing

Or

Was the material and construction the same as all the other stabis on the market that have not cracked up?
If the latter, then it is operator error
Either by manner of operation or how it was transported
May be not what the owner wants to hear, but still a possibility that the manufacturer has every right to expect to be able to check


Doing a brinnel test now most likely won't tell you much because the area will have work hardened
Besides which it is meaningless without specific reference points
I used to use 76mm tube that had to fall within a very specific brinnel range to be bendable
It could be well within mill specs and be useless to me because it would crack when bending, so every lot had to be tested
I seriously doubt any production boat manufacturer is using material that close to the edge as losses would be too high and it makes no sense from an engineering point of view on a boat.

I saw on another thread a surveyor is going to check it out.
I hope the matter is resolved to everyone's satisfaction



Cheers
Owen

Sent from my iPhone using Tapatalk


Brittle materials can be formed without cracking. Take stainless for example. The great thing about aluminium is that you have to flex it a lot to make it crack. Look at aluminium foil. I recall testing aluminium in a tensile tester at uni and mapping it to a graph when they were teaching us about youngs modulus and elastic deformation. You have to stretch aluminum a hell of a lot before it breaks.

The shear strength of aluminium is not quite as good, so when you design something out of aluminium you have to be aware of this. If the plate is cracking due to shear failure then that is poor design.

A boat should not crack like that. If its not material failure then its a design flaw. Eitherway, the manufacturer is at fault. No amount of abuse should cause cracking like that. This problem may well be occuring in other stabi's, we dont know. We have a 4.5m stabi at out VMR unit, so I am going to take a good look at that next time I am down there.

A brinell test would tell you if its material failure. I agree that a manufacturer would not use material not designed for the purpose, but this is not to say that the incorrect grade of aluminium was formed at the factory. Plus if the aluminium did come from china then there is no way of telling what other crap went in.

[business class]

Aluminium can delaminate and that is what has happened. Ive seen it do it to plate so you cant say it cant happen. The Manufacture is at fault here no questions asked and as the customer has supplied photos of the issue the manufacturer should be fixing this ASAP. will be interesting to see what happens

[Jarrah Jack]

Aluminium can delaminate and that is what has happened. Ive seen it do it to plate so you cant say it cant happen. The Manufacture is at fault here no questions asked and as the customer has supplied photos of the issue the manufacturer should be fixing this ASAP. will be interesting to see what happens

So a fix would involve much more than just welding over the cracks.

[TheRealAndy]

ITs not delaminating, its a shear fracture (In plane shear for the techos). There is no question regarding the failure. The question is what caused it. Welding over the cracks will not fix the problem.

[business class]

it would be interesting to take it to the aluminium supplier and see what they say. Im no expert in this but ive seen plate delaminate and that is exactly what it looked like. When the aluminium rep came out they replaced the whole pallet for us which was 3 tonne because of 3 sheets. to answer ur question from before...... No a simple weld aint going to fix this problem, its a massive job one would think.

[stinky-stabi]

well spent the last two hours with the fellow from KPS maritime and what a wealth of knowledge this fellow has, was very informative.
will have the written report tomorrow afternoon :-X,
can say the trailer was not the cause;D

[business class]

well spent the last two hours with the fellow from KPS maritime and what a wealth of knowledge this fellow has, was very informative.
will have the written report tomorrow afternoon :-X,
can say the trailer was not the cause;D

Im guessing delaminating????? and if thats the case a write off????

[Salad Fingers]

really doesn't look like delamination. Fatigue cracking is what it is I would say almost 100%.

Delamination in aluminium only typically occurs when two VERY different types of Al. are welded together.
ie, 5083 and 7075 or similar, creates a little mini battery with the 7075 containing copper and magnesium.
Not a very common thing to have occur. Also looks alot more like corrosion than cracking.

either way sounds like you're getting somewhere stinky-stabi (or should that be sinky-stabi now?) be interested to see what they say in the report.
My guess is that one of the ribs/stringers has let go and/or not installed correctly to begin with which has then caused undue pressure on the hull plates. :)

[Deanom]

My guess is that the base material has some flaws in it and is brittle as a result. Possibly the result of a manufacturing process at the mill that has invited impurities into the sheet.

[mitchdemeanor]

we should all have done a sweeps on this lol!

[TheRealAndy]

really doesn't look like delamination. Fatigue cracking is what it is I would say almost 100%.

Delamination in aluminium only typically occurs when two VERY different types of Al. are welded together.
ie, 5083 and 7075 or similar, creates a little mini battery with the 7075 containing copper and magnesium.
Not a very common thing to have occur. Also looks alot more like corrosion than cracking.

either way sounds like you're getting somewhere stinky-stabi (or should that be sinky-stabi now?) be interested to see what they say in the report.
My guess is that one of the ribs/stringers has let go and/or not installed correctly to begin with which has then caused undue pressure on the hull plates. :)

I have seen references to what they call delamination in aluminium, and its always been corrosion. See it more often on painted or treated aluminium. Cant say I know anything about it though, but I am sure google can provide the answers.


It would be interesting to see where the ribs are in realtion to that 'V' shaped crack. Thats the one that has me interested and thinking that it may be a flaw in the material.

[Dignity]

OMG - have to wait another day to find out the result, I hope the answer you have gotten will give you some resolution to the matter.

[Owen]

Brittle materials can be formed without cracking. Take stainless for example. The great thing about aluminium is that you have to flex it a lot to make it crack. Look at aluminium foil. I recall testing aluminium in a tensile tester at uni and mapping it to a graph when they were teaching us about youngs modulus and elastic deformation. You have to stretch aluminum a hell of a lot before it breaks.


Not that it serves any purpose with regard to the issue, nor do I have any reason to think the owner is trying a shonky, but in response to your post....

First of all, stainless and aluminium are so far removed from each other in their charecteristics that they don't belong in the same sentence.
The reality in practice is that you use the highest temper aluminium material you can reliably form.
The formers (presses, radii, etc) stay the same.. they are the constant.
If the material temper changes then the material either overbends (under temper doesn't spring), or it shows stress fractures (over temper doesn't have the elasticity)
Both are quite noticeable during manufacture (albeit they may not be rejected)

Youngs modulus has everything to do with this particular issue as I see it, but it does not automatically point to bad design or material. It merely illistrates that the loads (in this case) exerted exceeded the capabilities of the material/design combo.
It does not follow that the level of load, the position of load, or the frequency were at levels that fell within the design parameters of the hull.

A boat (or any structure) is designed to withstand a certain range of forces in a certain way.
Economics (and weight) determine that the materials used will handle that and not much more.
In the case of a boat it is designed to absorbe the weight and shocks of it's working load over the entire hull surface. How many psi is that on your graph?
You take that hull and put it on badly set up trailer that localises most of that weight on a very small area and at a frequency many times that of the ocean use and how quick does that reach the modulus and elasticity of the material? How many psi of force on that six inch square over the roller that's out of alignment?

It is ABSOLUTELY possible that the material was tempered too hard and as such has a shorter service life as a result.
BUT
For anyone to get on here and say from a couple of photo's that this is categoricaly a case of poor design or poor quality materials is bullshit.

In simple terms, when I take my 4.55 quinnie offshore and pound the shit out of it (as I do), I have no right to recourse down the track when it starts cracking up.
If I only ever tool around the estuaries as it was designed for and it cracks up, then I should scream blue murder.
Likewise, if I set the trailer up wrong and go for a drive to stanage bay once a month, it'll be stuffed in three.

[TheRealAndy]

Not that it serves any purpose with regard to the issue, nor do I have any reason to think the owner is trying a shonky, but in response to your post....

First of all, stainless and aluminium are so far removed from each other in their charecteristics that they don't belong in the same sentence.
The reality in practice is that you use the highest temper aluminium material you can reliably form.
The formers (presses, radii, etc) stay the same.. they are the constant.
If the material temper changes then the material either overbends (under temper doesn't spring), or it shows stress fractures (over temper doesn't have the elasticity)
Both are quite noticeable during manufacture (albeit they may not be rejected)

Youngs modulus has everything to do with this particular issue as I see it, but it does not automatically point to bad design or material. It merely illistrates that the loads (in this case) exerted exceeded the capabilities of the material/design combo.
It does not follow that the level of load, the position of load, or the frequency were at levels that fell within the design parameters of the hull.

A boat (or any structure) is designed to withstand a certain range of forces in a certain way.
Economics (and weight) determine that the materials used will handle that and not much more.
In the case of a boat it is designed to absorbe the weight and shocks of it's working load over the entire hull surface. How many psi is that on your graph?
You take that hull and put it on badly set up trailer that localises most of that weight on a very small area and at a frequency many times that of the ocean use and how quick does that reach the modulus and elasticity of the material? How many psi of force on that six inch square over the roller that's out of alignment?

It is ABSOLUTELY possible that the material was tempered too hard and as such has a shorter service life as a result.
BUT
For anyone to get on here and say from a couple of photo's that this is categoricaly a case of poor design or poor quality materials is bullshit.

In simple terms, when I take my 4.55 quinnie offshore and pound the shit out of it (as I do), I have no right to recourse down the track when it starts cracking up.
If I only ever tool around the estuaries as it was designed for and it cracks up, then I should scream blue murder.
Likewise, if I set the trailer up wrong and go for a drive to stanage bay once a month, it'll be stuffed in three.

My reference to stainless was nothing more than pointing out that brittle materials can be formed without fracture.

Youngs modules was also just a reference to what I have observed at uni doing tensile testing and pracs whilst learning to understanding elastic deformation.

Aluminium is a great material. Many boats get pounded in rough seas with no issues. Why has this boat failed? We have not seen the design of the boat, so no one is claiming that it is definatly material failure. What ever the reason, the pictures cleary show abnormal failure. Its not from abuse and anyone with engineering backround will not disagree.

[Mr__Bean]

Can we stop the pissing contests?

Darren

[DOGFIGHT]

Good reading Owen, you seem to know your stuff

[Owen]

Can we stop the pissing contests?

Darren

Andy and I are just giving our opinion based on our respective experiences and understanding of aluminium and fabrication.
His experience is valid, and I have not said his analysis is wrong.
I merely take issue with arriving at a conclusion based on the photo's shown.
They definately show a boat were something is outside the design parameters.
They do not exhonerate (or condemn) either the owner, or the builder.

As Forrest would say.

"That's all I have to say about that"

[bigjimg]

Can we stop the pissing contests?

Darren
I thought the responses from both sides just good debating and was enjoying the read.Stinky hope your problems are resolved quickly,although I would suspect your confidence in this boat has taken a hard hit.Jim

[Mr__Bean]

Hmmmmm,

Head suitably retracted.

Darren

[stinky-stabi]

looks like the problem was smaller plate used between floor and hull which has broken welds off causing hole underneath , last 400 mm of boat has no welds on longtitudal beams causing rest to flex thus cracking,,, just a quick insight as I understand it , will post report when I have it in my hands.,,, have been told to do a few mods to strengthen things up all-round so will be done next week an ready for Fraser trip ,) and finally headn out for a run tomoz " tight lines"

[mac64pc]

in my humble opinion knowing very little re tinnies.....

If the product is sub standard then they should fix the issue free of charge

If they have a new model coming out :P and they dont want negatives....they should replace free of charge O.o ..

these guys arent stupid get the posts removed so it doesnt impact future business, but I wouldnt stand back and take it, the product has clearly failed and I wouldnt hesitate to broadcast the issue in as many forums as possible

If you dont get a replacement or at least a fix with a guarantee against further issues you have been dudded...................

fixing your issue is small bucks in the scheme of things vs the negative publicity you can generate

[Jarrah Jack]

Thanks for that SS. Makes you wonder if they are all built like that. Would be nice if Stabi could get on here to their Aussie market and explain things.

[Dignity]

Glad to hear you can get the boat fixed and have some confidence in it again. BTW when are you heading up to Fraser.

[stinky-stabi]

Glad to hear you can get the boat fixed and have some confidence in it again. BTW when are you heading up to Fraser.


yes indeed , heading up Frazer last week of July , should have me report tomorrow as old mate sent it in the mail ??

[Dignity]

Snail mail isn't too shabby these days, you should have it by now. I hope to be up there 1st 2 weeks of July, will give you a report on my return.