Crack in body shell - what should I do?

[TheCheltenham]

I was checking over our Bailey Orion (2012) at the weekend and saw we have a thin 2.5 inch crack in the Alu Tech body shell above the wheel arch. Can I fix it? We are out of warranty. What should I do?

Here's a photo with the detail:

 

[Mr Plodd]

Assuming it's GRP and not aluminium a bit of Captain Tolleys Creeping Crack Cure would be my suggestion.
The sidewall outer skin is exceedingly thin so as long as its watertight I wouldnt bother about it too much. Judging by its location I would imagine its run from the screw thats holding the wheelarch spat on (no pilot hole drilled prior to the screw being inserted woukd be my guess as to the cause)

 

[Deejuk]

Personally, if it is GRP I would put a very very small pilot drill hole at the end of the crack to stop it from cracking any further and then coat it with epoxy. I have read some good things about Captain Tolleys stuff but never used it, Plodds suggestion may be the better route.

Another option I've seen is plastic welding the gizmo for doing the job aren't too expensive on Amazon - https://amzn.to/3xOgNj7

Anyway that's my twopeneth - good luck with it though

 

[Jcloughie]

I believe the panel is aluminium. Perhaps it has hardened with age but normally aluminium is sufficiently supple and can handle a little movement.

I agree that it very likely stems from the arch screw, at least it will be stopped at the vent.

I do not see a structural problem, but feel it could do with being opened into a ‘V’ shape and filled with a fiberglass filler. It will be difficult to do an invisible finish, but preventing damp and stopping it getting even worse would be my priorities.

John

 

[TheCheltenham]

Assuming it's GRP and not aluminium a bit of Captain Tolleys Creeping Crack Cure would be my suggestion.
The sidewall outer skin is exceedingly thin so as long as its watertight I wouldnt bother about it too much. Judging by its location I would imagine its run from the screw thats holding the wheelarch spat on (no pilot hole drilled prior to the screw being inserted woukd be my guess as to the cause)

Thanks! I'll give that a go.

 

[Dustydog]

The Bailey Orion 2012 has a GRP outer skin . I’d do exactly as all the others have said. I have used Capt Tolleys for the last 7 years on two minor cracks on the rear panel. The crack has never opened nor spread any further than the pilot hole I drilled. I apply CT every years as a belts and braces. My panel is ABS.

 

[Jcloughie]

In #4 I said the panels are aluminium. I said that because new ones are, also the 2012 Alu-Tech Unicorn I had, had aluminium sides.

Now looking at a 2012 brochure I see that the Orion had GRP at that time.

I was assuming all Alu-Tech used the same construction.

So please ignore #4 😡

John

 

[Dustydog]

In #4 I said the panels are aluminium. I said that because new ones are, also the 2012 Alu-Tech Unicorn I had, had aluminium sides.

Now looking at a 2012 brochure I see that the Orion had GRP at that time.

I was assuming all Alu-Tech used the same construction.

So please ignore #4 😡

John

I wonder? Looking closely at the photo it could be aluminium, a strange too perfect crack for a gel coat GRP maybe??

 

[JTQ]

I suspect it is "structural" though of limited concern. It is positioned where the ultra stiff [in the vertical plane] side member, is stress raised by the wheel arch cut-away and the lower fridge vent, at where the structure will hog over the axle area. [ if asked, pre the event, where such a design might fail, I would have drawn a line near there]
Our caravan box construction is as said ultra stiff but physically weak, so as the van bounces along on what is an excuse for a chassis, stiffness wise, things have to move, and that finds the weakest point. Like it has.
The flexing is going to happen, and in itself that is not a problem, its better in someways it does than have an ultra stiff, very wek component trying to stop it.
If I am right, then the "repair" needs simply to return the watertight integrity, not a "hard" repair that chases the fracturing elsewhere.
Therefore I would put a plate over it, covering a cm each side of the crack, bonded on with something like a polyurethane agent like one of SikaFlex's, where you leave at least a mm of bonding agent, not squeeze it out, it needs to have that bit of compliance.

Then enjoy caravanning, and don't worry, knowing the damp integrity is back there.
Engineers design things to flex, where its not realistic to do otherwise; peek out of airliner window, as the plane takes off, or even taxis round the perimeter track.

 

[Jcloughie]

I wonder? Looking closely at the photo it could be aluminium, a strange too perfect crack for a gel coat GRP maybe??

I found a Bailey Orion brochure for 2012 which said GRP. But my Unicorn was Aluminium.

I suspect it is "structural" though of limited concern. It is positioned where the ultra stiff [in the vertical plane] side member, is stress raised by the wheel arch cut-away and the lower fridge vent, at where the structure will hog over the axle area. [ if asked, pre the event, where such a design might fail, I would have drawn a line near there]
Our caravan box construction is as said ultra stiff but physically weak, so as the van bounces along on what is an excuse for a chassis, stiffness wise, things have to move, and that finds the weakest point. Like it has.
The flexing is going to happen, and in itself that is not a problem, its better in someways it does than have an ultra stiff, very wek component trying to stop it.
If I am right, then the "repair" needs simply to return the watertight integrity, not a "hard" repair that chases the fracturing elsewhere.
Therefore I would put a plate over it, covering a cm each side of the crack, bonded on with something like a polyurethane agent like one of SikaFlex's, where you leave at least a mm of bonding agent, not squeeze it out, it needs to have that bit of compliance.

Then enjoy caravanning, and don't worry, knowing the damp integrity is back there.
Engineers design things to flex, where its not realistic to do otherwise; peek out of airliner window, as the plane takes off, or even taxis round the perimeter track.

Thinking about it, when my 2012 Unicorn Alu-tech had a wheel detachment, after the extensive repairs were done a small crease appeared above the door. The insurance assessor said that will be easily fixed. Bit Bailey insisted on replacing the whole side.

So I dare say you are right. And the repair you suggest sounds sensible.

John

 

[ProfJohnL]

The use of Captain Tolley's does not produce a very strong bond, so if there is any movement in the crack when the caravan is moved, the filler will lose integrity. If there is no movement then Tolly's should seal the crack.

 

[trevormonty]

If its GRP glassing woven mat over crack is strongest repair but it will be ugly. Can smooth and paint but will always be raised surface. This is my standard approach to boat repairs and not failed me yet.

 

[Mr Plodd]

The use of Captain Tolley's does not produce a very strong bond, so if there is any movement in the crack when the caravan is moved, the filler will lose integrity. If there is no movement then Tolly's should seal the crack.

It's not a "bond" thats required, just sonething flexible to seal the thin crack, hence my suggestion of Capt T's (which cures clear)