Engine Bay,Filling Seams with body filler

[808wish]

Hi all, I am new here and just after some info on the following.

I have an RX7 series 1, that I am doing a resto on and am planning on making it a show car etc so want to smooth out as much as possible in the engine bay and all over basically.

The biggest thing that irritates me on cars is the seams that are spot welded and seam sealed. I want to fill and smooth theses areas for the nice and clean look.

The RX7 is in very good condition body wise, no rust and all seam sealant is in place and it is fully filled:ie no holes for moisture to come through etc.

Questions are:

1: Can I use a body filler to fill the ugliness of the seams so I have a nice clean smooth surface?

2: if I do is there any risk of cracking from movement etc?

3: If there is risk what is the best method of filling and smoothing out the seams?

4: If I need to weld, is there a specific technique used ie: do I have to weld the full seam or can it just be short half inch to an inch section in various spots along the seam?

I will probably have many more questions which will include painting advice as well as I plan to do the whole thing myself.
Thanks in advance for any advice given.
Cheers
J

 

[rikrobson]

I'd be tempted to clean up the seam sealer and re-seal smoothing out before it sets the paint as normal. filler is going crack if the panels flex against each other. The seam sealer stays soft and plyable whereas the filler will be hard and brittle. there may be soft fillers that would do the job. if there are any suitable i'd expect them to be available at frosts.

With regard to the welding, a replacement panel can be fitted using the original manufacturers method i.e. spot or plug welding. Any repair panel needs to be fully seam welded or its going to fail an MOT.

 

[brightspark]

i would have thought if it was a show car it would have to be as near as posible to the original manafactures design including showing the spot welds and the seams

 

[malcolm]

I'd not trust plastic filler on seams - I've used it on external seams and it does tend to crack with time, either through the slight movement you get or the moisture that invariably finds it's way into the seam.

You can get a reasonable result with Polyurethane seam sealant. That can be smoothed with a rag or finger soaked with thinners after application (see http://www.mig-welding.co.uk/seam-sealing.htm for the results)

Lead loading would probably be the best way to do it. It's what they used before plastic body fillers and doesn't crack, but it would be fiddly to use in the engine bay.

A horrible approach would be seam welding the seams and then using plastic filler over the top, but the seams will be contaminated by old sealant that you can't remove so welding will be a pain, it's tricky to grind off excess welds in tight areas, there's a risk of distortion, and it will likely end up a mess unless you use a lot of filler.

 

[Chipper]

Could smooth the sealant as much as poss, then spray stonechip with a spray gun for a nice smooth finish.
But as said, depends what sort of show you're aiming for, smoothing won't please rivet counters.

 

[808wish]

i would have thought if it was a show car it would have to be as near as posible to the original manafactures design including showing the spot welds and the seams

Hi brightspark, By show car I am meaning a fairly detailed engine bay and rest of car, hidden wiring polished alloy parts etc etc. I did think of going down the stock standard rebuild back to original, but as stated before I am very much into creating very smooth and clean engine bay etc. I really dont like the clutter that is put in cars. Even though manufacturers build them that way to specs.

In looking at the car I note that the original seam seal that has been painted over by the manufacturer has not cracked so that would indicate very minimal movement. I plan on a strut brace as well to firm it up abit also.

 

[the snooper]

In looking at the car I note that the original seam seal that has been painted over by the manufacturer has not cracked so that would indicate very minimal movement. I plan on a strut brace as well to firm it up abit also.

dont be fooled seam sealer is very flexible i would saty well clear of filling the seams with anything like body filler it will be sure to crack

 

[808wish]

Thanks for the advice all, I will definatley be keeping the seam seal or redo it before I move on further to smooth and clean, I will probably try and keep an extended gapping if I need to fill in with body filler and include a flexable filler to reduce the cracking issue.