Silicon Sealant questions

[HaX]

Hi there,

The seals around the rear light clusters on my Mondeo were leaking water into the boot, so I took my car round to a m8 who is a mechanic.

He put some all purpose sealant between the clusters and the body of the car which should hopefully have cured the problem.

However, one thing which I've just read on the internet is that during the setting process, Silicon Sealant produces Acetic Acid which can disolve paint.

Is this the case? Am I likely to get rust forming behind the light cluster? Cheers

HaX

 

[saitrix]

It does produce the acid, just not sure what effect it would have on paintwork.

 

[Mic]

I think you have to use 100% silicon or something so it doesnt rust. *not too sure*

 

[Bear]

You can get non corrosive silicon sealant, we use it at work and would guess thats what your mechanic mate would have used. Would be daft to use it otherwise.

 

[Chabsy]

yes neutral cure stuff would have been best, did it smell of vinagar? if it didnt then its neutral cure

 

[Jonny69]

sure it'll be fine. Once it's cured it won't eat the paint.

 

[jonneh]

my advice is dont taste it, its mingin.
so will the kitchen and bathroom sealant i used to mend a customers light eat her paint?? it was homebase own brand??

 

[Muncher]

Sikaflex 291 which is commonly used is fine on paintwork.

I would guess that if it spelt extremely strong I would be more concerned. Sikaflex has no smell an is what Lotus use to stick stuff together.

 

[Dr Who]

My kit car bodywork is held on with that stuff... (sikaflex)

PU adhesive is awesome

 

[HaX]

Just checked my car out - he had useed Decorators Caulk which is non-corrosive and also useless at keeping water out - as i've just discovered water in my boot again.

I'm going to have to go and find some neutral curing (non-corrosive) silicone sealant or something similair. Any ideas of where would be a good place to get some?

 

[andi]

If you can, get some non-setting mastic from a caravan place (used to seal caravan bodies). Its what most manufacturers use to seal in lights.

 

[MrCake]

If we are talking about a mk2 mondeo then it might not be just the light clusters. My st200 had corroded seals on the lights so I ran round a bead of sealant but when I tested (seats down with a mate pouring water over the back) it was still coming in.

My secondary leak was coming from the grommet on the rear wiper. Take the arm off, remove the grommet, and then apply some vaseline or something and refit making sure its a flush fit.

Since doing that to mine, I no longer get a boot full of water.

 

[Malachy]

Just checked my car out - he had useed Decorators Caulk which is non-corrosive and also useless at keeping water out - as i've just discovered water in my boot again.

I'm going to have to go and find some neutral curing (non-corrosive) silicone sealant or something similair. Any ideas of where would be a good place to get some?

check the boot lock assembly a friend had this leaking on his mondeo took a while to diagnose as everyone said it was the light cluster due to it being a common failure.
just took the lock assembly apart and rebuilt using sealent.no more leaks