filling in a sunroof

[woodyracing]

I was looking at stock/hot hatches the other week and most of them were cars which had a sunroof, the solution on most was to rivet a sheet of metal over the where the sunroof was but this looks rather crude. So how easy/expensive would it be to fill it properly so you can't tell a sunroof was ever there (from the outside).

cheers

[phatgti]

It may look crude but it is the lightest and safest way if you use thin steel sheet (20 gauge?)

[Al Weyman]

I had a bigger problem with my IROC. Like the Rover Tomcat it had a T-Top roof. I took out the glass panels and had a couple of sheets of steel rolled and cut to shape, we then welded them in place with a trim and thay looked very neat infact I don't think any one has ever took any notice of them. So for a start I would get a sheet of metal rolled not try to bend a flat sheet across, prehaps get an lip bent around the edge to give some rigidity and exactly the same size as the original roof then maybe you can sink it into the aperture with a trim around it and make a feature of it so in fact it looks (like mine does) a painted metal sunroof but it will keep the scruts happy. I would say thats the neatest way to do it apart from that if its a common car try to cut a roof off from a scrap yard.

[woodyracing]

also how would you make it water tight ? I have seen some cars with tank tape around the metal sheet they had riveted on.

[Al Weyman]

Easy, just leave the original aperture as it came from the factory and insert the new section into that with some sort of seal (never heard of silicone mastic :-)), many like my old Omega have a drain off.

[Chris Y]

Oh for heaven's sake Woody, just get a sheet of ally or steel, rivet it in place, and put a bit of silicone sealant around the edge to stop the water getting in! So, it won't look perfect, but it will look neat enough for racing purposes, and reasonably leak proof too.

[woodyracing]

Originally Posted by Al Weyman

(never heard of silicone mastic :-))

no but I have now

Originally Posted by Chris Y

Oh for heaven's sake Woody, just get a sheet of ally or steel, rivet it in place, and put a bit of silicone sealant around the edge to stop the water getting in! So, it won't look perfect, but it will look neat enough for racing purposes, and reasonably leak proof too.

true but there is the option of avoiding a sunroof all together

[MGDavid]

you may be surprised how much the average sunroof cartridge weighs - the opportunity to remove 10 or 20 kilos from the highest point on a car is not to be sniffed at. Remove the lot, and replace with a steel panel with flanged edges that just slips in place, then weld in place, fill and paint. You may want to weld a couple of light stiffeners on the underside to prevent drumming.

[woodyracing]

Originally Posted by MGDavid

Remove the lot, and replace with a steel panel with flanged edges that just slips in place, then weld in place, fill and paint. You may want to weld a couple of light stiffeners on the underside to prevent drumming.

would you weld the panel on to the top of the car or underneath where the sunroof was ?

[scrutineer]

true but there is the option of avoiding a sunroof all together

Have to agree, if you are having a stock hatch there must be loads of them about with and without a sunroof, find one without.

[StephenRae]

I would cut a section a couple of inches bigger than the aperture from a scrapper and stick it on with sikaflex, four countersunk rivets in the corners would do. The shape will already be there and if you are lucky you may even find one in the right colour!

[dtype38]

Originally Posted by StephenRae

I would cut a section a couple of inches bigger than the aperture from a scrapper and stick it on with sikaflex

Best solution so far For an invisible mend you'll need to use a flanging tool around the edge, but I think an inch overlap would be plenty. Then make sure that you get Sikaflex "panel adhesive". They make lots of other stuff, but the panel adhesive is suitable for semi-structural joints and will be more than strong enough for this purpose. Then filler the joint on the outside and paint as normal.

[woodyracing]

thanks for the ideas so far, i am a newbie when it comes to metal work luckily I have someone to help me out though. Using the method above would that leave a slight bulge ?

any pics of peoples filled sunroofs ?

cheers

[glenn22481]

Iv'e done this before on a few cars but I work at a bodyshop so have all the tools required.. Best way is to find a 2nd hand roof skin, cut out the section required and allow a 10-20mm overlap using a flanging tool, bond on with 2k epoxy adhesive (terrokal 9225, or 3m panel adhesive, or ixell panel adhesive - all work well and this is what they are made for; you can even bond 1/4 panels on with this stuff) and let it cure while holding it inplace with some 1/8 cleco clips. When cured the epoxy adhesive (which is excellent for it's gap filling ability and ease of sanding) will be actually stronger then if it was welded on. Remove the clecos and use a Jetspot pin machine or similar to weld pins on where the holes are from the clecos (yuou could weld these but it will destort the panel), cut and trim these flush with the panel and if you are really good finish off with a single skim of bondo. The inside should be treated with some rust prevention and all seams sealed and painted. If done correctly you shouldn't need to fit any kind of reinforcer or stiffener to the inside as the flange alone will add a fair bit of strength to it. If you do fit them, fit them AFTER you have filled it smoothe otherwise it will make it hard to avoid a rippled finish.

It's worth telling your painter to give it a low bake rather then a high bake when it gets painted to avoid possible sinkage - unless you pre-bake it before you fill it (which if you are fussy is worth doing as it will add considerable strengh to the epoxy bond). A heat lamp overthe panel for an hour will have the same effect - just dont get it too hot (if it's feels hot to the touch it is too hot).


IMHO - it's not worth the effort, i only did it because I couldnt persuade the customers to save their money, one of them rolled the car not long after.. Sods law and all that....

[MGDavid]

Originally Posted by woodyracing

would you weld the panel on to the top of the car or underneath where the sunroof was ?

the replacement steel sheet with flanged edges drops into the hole after removing the sunroof. Mig weld from the outside, grind off any excess weld. You should not get any warping and the finished job should be smooth. If you PM me an email addy I'll send some pics...

[R59]

Depending of the make/model of the car, check out your local body parts supplier, and get a complete roof skin.

I reskinned my Nova after first of all running a 4mm sheet of alloy in place of the glass (it was an aftermarket naff sunroof), then filling the hole in properly, with a nicely rolled piece of steel, which once welded warped more than the Rocky Horror Show!

So, get a full skin! Whether it's skilfully cut from a scrapper, or a new one, up to you. It'll save you some weight too! No nasty filler to make the welding/rivetting look nice.

It's also easier to fit.

Rob.