FAQ Input : Repairing Tank Inserts for Shrouds.

[jeffd]

Question : I crashed hard and the inserts/threads pulled out of the fuel tank where the shrouds mount on. How can I repair these?

Answer : There are two methods that can either be used individually or possibly used in concert with one another if the damage is great. With either method - safety measures should be observed. Drain the fuel tank and fill it with an inert gas (nitrogen) to avoid combustion from occuring (okay the lawyers are happy now...).

The first method is to purchase brass inserts and use these in place of the plastic inserts that come on the tank stock. These inserts are available through McMaster-Carr; The part number is 94510A050 - this is for 25 brass inserts and sells for less than $10.00.

If the damage is extensive and the metal inserts alone cannot be used, then the second method for fixing the damaged inserts is to use an airless plastic welder. Inexpensive models can be as little as $30 and yield mixed results. A professional model such as the matco APW1000A yields professional results at a professional price and will set you back $241.70. There are two "rods" available - polyurethane should be used.

If you like to do collect tools like I do, then method #2 doesn't seem so bad. Obviously a more cost effective fix is to empty all fuel from the tank and let it air dry; Order up some of the brass inserts and then take it to a body shop that does bumper repair and have them do the repair for you.

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jeff

 

[INABIL]

My screws ripped out of my tank on one side so I emptied the fuel out, dried the inside out with my air compressor then took a lighter to where the screws ripped out. After putting the flame in where it ripped I used the flat spot on my rachet wrench extension to push the melted plastic back into the hole. After it dries the same screws hold pretty good.

 

[MattR]

I emptied the fuel out, dried the inside out with my air compressor then took a lighter to where the screws ripped out...

IMHO, flames and potential stray gas fumes is too risky. What about the gas that soaked into pores of the plastic? I'm not even sure if filling the tank with water first, then doing this type of repair would help.

Perhaps using a soldering iron and melting the plastic would be less risky.

 

[stay_upright]

I've attempted this repair a few times using brass type inserts.

The best method is to use a M4 insert (or a short M5 insert) cut a bolt head off a bolt leaving the thread only and thread in all the way into the insert. Next take the regular tip out of a soldering iron and lightly clamp the bolt in there with the insert attached to the end.

The widest part of the insert needs to go in first so it is buried deep in the plastic and will not pull out (my first attempt were with the lip the last part to go in and is not as strong)

Next turn the soldering iron on and have a screwdirver ready to undo the bolt thread from the iron once its in to allow it to cool. Push the brass insert against the tank with a moderate pressure and as it heats the insert is buried in the plastic. Note it will go in so far and then seem to stop - this is because the plastic melting around the insert has filled up the area in front of the insert and now has no where to go - keep pushing and wait a bit and the plastic heats up some more and flows around the lip of the insert and will also fill in any air gaps near the front (closest to you) of the insert leaving it fully enclosed. Once fully in undo the bolt/insert from the iron and beware there will be a bit of trapped air and it may start pushing the insert out - you need to hold it with some pliars and let it cool.

Note if you do this without a bolt/thread in the insert it the plastic will flow into the inside thread and stop you putting your own bolt in.

Finally I did this with 1/2 tank of fuel - there are no naked flames and the parts don't get hot enough to ignite fuel.