Rust on sills

[kaine2010]

is there anyone who is able to help me i have a mk3 golf gti and discovered a lot of rust under the plastic trim how do i go about sorting it out do i have to replace the sills or can i treat it myself using a industrial strength rust acid ?? how much am i looking at in replacing the sills its a 3 door gti please helllpp !!!

[xxChrisxx]

is there anyone who is able to help me i have a mk3 golf gti and discovered a lot of rust under the plastic trim how do i go about sorting it out do i have to replace the sills or can i treat it myself using a industrial strength rust acid ?? how much am i looking at in replacing the sills its a 3 door gti please helllpp !!!

Well it really depends what 'a lot' is.
Sounds like a welding job to me.

[kaine2010]

Not too sure its 15 years old I don't know weather to take the plastic covering off to view the whole sill the bit of plastic that's broken is near the front drivers side and looks really bad just wondering if its worth Replacing both sills as I plan on keeping the car if i get it fixed I think the plastic covering is hiding a lot of rust underneath

[trog_nfs]

Chances are its going to be very rusty under the plastic sills, will be worth taking them off completely to assess the damage. Also the factory sealent tends to hide a lot of rust too. Probably find under the arch trims it's going rusty too, very common problem.

As sills are structural you must get new panels welded in properly if you are going to address the problem. You can buy replacement sills to weld in yourself, or take it to a good garage if you're not too competent with a welder.

Ring around garages to get some ideas on price, unfortuneately it varies a lot area to area

[VR6_Wherry]

Take it all off, that is the only proper way to find out how bad the rust really is. If it's bad then it needs to be cut out and welded.

[Gti_Jamo]

They usually rot out at the front and back of both sills usually at jacking points. Patent sills can be bought of ebay for £15. You could either replace the lot or just the sections that have rotted out. Any surface rust can be ground down to bare metal and treated with rust killer. Best bet is to get the grinder out and see what is what then you can go from there. Beware to check where the sill meets the floor as this can also be a problem. I've just done a power of welding in my Mk3 build thread below including a sill so have a look if you want mate.

[tshirt2k]

Take plastic off. It a rust trap. Only get metal replaced that is rotted. Recently did this on mine and the rust tends to creep under the factory sealant and looks ok. The plastic grommets on the outer edge of the floor pan also rust. Near side is usually worse due to being next to pavement and having more puddles And debris there. 

[kaine2010]

will take it to the garrage this afternoon as i dont think i will be able to do it myself thanks for helping will keep you posted i think the car is worth keeping as it has a full service history from vw and only had 2 lady owners will take the covering off tonyt and assess the damage to see if i can just chop the bad bits out

[Ant1981]

Don't worry about it, comes standard with MK3's.

[danny_p]

you can ignore it, the rustworm need to eat something and theve nearly  eaten all the BL sh!te that was ever made.

or pay lots of money to have it fixed,  often ends up been quicker and easyer to swap the whole sill out imo