Repairing arm on roof box

[Bluebirdnick]

Hi all

I've borrowed a roof box and have managed to break the arm at the back which holds up the lid. Not sure how I broke it, I was super-careful with it as it's not mine, but broken it is. I attach some photos to show the damage, and would appreciate thoughts on how to repair it or what sort of tradesman I can take it to to fix it. I'd rather pay someone to do it I think. I am thinking of attaching a metal plate over the break and some sort of rivet to attach the arm to that plate - does that sound right, and if so, where might I take it for someone to do that properly?!

Thanks!

Nick

 

[Burnerman]

Bit of a difficult one to make beautiful Nick, but you're right you need to over plate the hole with some aluminium sheet and secure that with pop rivets - those rising stays are quite powerful.
You could plate the inside too before securing the stay bracket....it could depend on what thickness ally you had available.
Not a difficult repair which would be stronger than original - but I guess that's up to the owner!
Bad luck - I bet it was ready to fail before you borrowed it!
John

 

[Bluebirdnick]

Thanks John. Any idea where I might take it to get it done?

 

[Burnerman]

Hmmm that's a difficult one......obviously its not a garage or Halfords job and most would claim its hardly worth the bother. As these boxes are often made from ABS they become fragile anyway. You need a 'handyman,' if such a person exists.
Do you know anyone with a pop rivet gun and a drill? Seriously it would take less than an hour to sort that with a rectangular aluminium plate with rounded corners and a few rivets plus washers.
John

 

[Bluebirdnick]

Thanks John. I suspect I'll just do it myself then - Looks like it was held together with pop rivets before. I've never used a rivet gun before and would rather have someone with professed expertise do it and I pay, just to show the owner I've done what I can. But a rivet gun seems to be quite cheap, and I can have a bit of a practice before

If I were to do it then, I think the plan is:

1) Get hold of two square aluminium plates, same size, say approx 3mm thick. Drill holes for rivets in each of the four corners, same position on both plates
2) Attach the stay bracket to one of the aluminium plates (say 3mm thick) using rivets. The flat round end of the rivet to go on the aluminium plate side
3) Temporarily fix aluminium plate with say bracket attached, to the inside of the plastic box with glue. Drill through the holes in the corners of the aluminium plate, and the plastic behind. Fit other aluminium plate to the outside of the plastic box, line up the holes and rivet through to join the two aluminium plates, sandwiching the plastic between them.

Does that sound about right? Thanks

 

[ETAF]

Just an idea, as it may be fragile now and not long before the TOP bracket has the same issue - have you thought of just having the conversation with the owner first
NOT sure of the size , but a halfords replacement may only be £130
https://www.halfords.com/motoring/r...MIlcrJ1J3m6wIVia3tCh3E5gFIEAQYASABEgKv2_D_BwE
And maybe you could come to some agreement and pay towards a replacement.

Not sure what a professional repair would cost you.

 

[Burnerman]

Thanks John. I suspect I'll just do it myself then - Looks like it was held together with pop rivets before. I've never used a rivet gun before and would rather have someone with professed expertise do it and I pay, just to show the owner I've done what I can. But a rivet gun seems to be quite cheap, and I can have a bit of a practice before

If I were to do it then, I think the plan is:

1) Get hold of two square aluminium plates, same size, say approx 3mm thick. Drill holes for rivets in each of the four corners, same position on both plates
2) Attach the stay bracket to one of the aluminium plates (say 3mm thick) using rivets. The flat round end of the rivet to go on the aluminium plate side
3) Temporarily fix aluminium plate with say bracket attached, to the inside of the plastic box with glue. Drill through the holes in the corners of the aluminium plate, and the plastic behind. Fit other aluminium plate to the outside of the plastic box, line up the holes and rivet through to join the two aluminium plates, sandwiching the plastic between them.

Does that sound about right? Thanks

That's the sort of thing Nick.
I think you are going over board a bit with the material thickness - 3mm is bar rather than sheet, and won't follow the curvature of the box - if it has any. 1mm would be fine if you are using it as a sandwich.
I'd go for 4.8mm rivets (5mm hole), say 10mm long.
Hope it goes well!
John

 

[Bodgedbuild]

ABS takes to being glued exceptionally well. I would repair the broken part, make good cosmetically and then move the strut slightly. Also you can make ABS paste using Lego and nail polish remover (if you have no Lego, rear lights on cars are normally ABS) the paste can be used as a filler or to thicken the repair area if required. It is easy to test if it is ABS too, apply nail polish remover to a cotton wool pad and rub it on an area not normally seen. ABS will get a sticky surface straight away, other plastics won't react.

 

[Bodgedbuild]

..............You can also buy solvent weld pipe to use as a filler/thickener or to make a paste with if you prove the box to be made of ABS

 

[foxhole]

Drill out rivets and patch hole with fibre glass then refit bracket with large washers or a metal plate to out side to strengthen repair.Simple repair.

 

[domdee]

Get some spreader plates for both internal and external. Drill them off. Apply some from of sealant under both plates.

Then fasten all together. I wouldn't use pop rivets. I'd get some m3/m4 stainless flange dome head bolts and nylock nuts.

If you haven't got the correct grip length rivet you can do more damage than good, or not have it securely fixed.

With the nut and bolt you can feel the materials grip and tighten according to the 'feel' of it.

 

[Bluebirdnick]

So this did actually get fixed - thanks for the help. At the last minute I myself decided on the course of action that Domdee sets out- it's not my roof box so wanted the owner to be able to undo it himself easily if needed (he's handy). I was looking forward to using the rivet gun, but have two other projects that call for it too so it won't go to waste. It went quite well. A bit of a messy fix, but it's solid enough and won't break. To be honest the plastic fixed well enough to support the arm alone, but put plates on anyway to be sure:

 

[Bluebirdnick]

 

[Bluebirdnick]

 

[Bluebirdnick]