Issue with making a seal with tail lights

Hi folks April 2008 i bought my new micra and replaced the tail lights and side repeaters - thanks again to smidge for the advice on that.

I've posted a pic this time :-)

9 months later at the recent MOT test it failed on being severely corroded on both sides at the back of the wheel arch. the MOT guy said it was probably channelled water from the sunroof it had collected there and then caused rusty holes.

Do you think its because i didn't fit the tail lights correctly, and water has got in and been unable to escape? I do!

I've now had the welding done and don't want this to happen again.

What's that black gooey stuff that holds them on and makes the seal? at the time of original fitting i didn't think about this at all but i reckon this is what is needed to make a good seal.

Any advice much appreciated
Adele UK

the black stuff is called sikaflex here, its like a black and super sticky silicone, its a good idea to use it when replacing the tail lights, micra's (and lots of jap cars) need the stuff or, yeah water gets in everywhere

replaced some tail lights on a golf recently and none of that stuff was needed which a nice surprise

Hi again Smidge and thanks for the info. I see that i can get a tube of the stuff on ebay but i'll try my local shop first as i want to get moving on this straight away - middle of winter here so lots of rain!

Do you think its best to remove as much as possible of the old gooey stuff before applying the new? Or does it ALL need to come off?

A

I would not recommend using sikaflex.

It dries very hard and is one of the strongest (flexible) adhesives known to man.

If you were to use sikaflex on properly cleaned and prepared surfaces I doubt that you would ever be able to remove the taillights without destroying them.

The type of sealant used is generally referred to as mastick.

It never goes hard and therefore will not permanently glue the lights in.

Yeah you definitely don't want something that sets rock-hard. This has got me worried - I replaced mine about 6 months ago and didn't renew it as the ones I got had about the same amount of sticky stuff if not a bit more.. tried to make sure they were sealed enough but I guess I should do a checkup.

Any pics of where the water was pooling?

Edit: though.. channeled from the sunroof? Don't have one on mine and can't really picture where water could come through the sunroof to affect that area. Again.. pics! :P

---dens

Hey,

As far as Im aware, there are lots of different types of Sikaflex with different properties.

Here is a link to just some of the auto ones.

http://www.sika.com.au/cmi/auto_products_adh.htm

Surely there is something similar in the uk??

Thanks
qwerty132

hey adele if you check out ur local Partco Autoparts shop they may sell some PU sealant for afew quid.

i've used it to bond me rear spoiler on and to seal me windscreen edge. sets in hours and is really tough, rubbery n watertight.

I use roof and guttering sealant from b&q works a treat and doesnt set so you can remove them again. only a few quid a tube.