markw's 1973 Fiat 124 Sport Coupe discussion

[markw 50]

Discussion thread for my rebuild.

[ThePog 6,065]

I had a silver CC for a while, it was a great car. It had a 2 litre in it, went hard for what it was, so I imagine a volumex would be pretty good. It needed rust work virtually every wof, just as well I had a welder...

[markw 50]

The volumex is good, but a little choked up. I'll fix that.

[Testament 8,273]

17 hours ago, markw said:

The volumex is good, but a little choked up. I'll fix that.

yeah the volumex is good, the inlet manifold is not the greetest mostly. all of the talks though, just for lols drove my 124vx from thames to coroglen in 5th gear at coronats way back when.

Crossing fingers that going to sequential injection is going to solve the majority of the issues I've had with mine being a piece in one way or another.

I wonder mark, do you know Steve Spiers and Blair Wald? I remember Steve telling me about a 124 coupe with VX kicking around auckland a million years ago. 

[markw 50]

@Testament I'll be watching your sequential injection adventures keenly. Have been wanting to do something like that for a long time, but the effort level is high. I'm also following your drive-train adventures, having just purchased a 131 box for the project. Body work first though, which isn't something I'm versed in.

I know Steve, and have met Blair, so this is probably that VX, and a million years ago sounds about right (I've been away for a while).

[Justing 0]

I’m currently rebuilding the engine on my 74 124. Stock 1.8 but I’m refreshing the bottom end and warming up the head etc. These are total unicorns these days so good to see more! 
I don’t envy you on the bodywork front. 

[Nominal 48,735]

Looks like insufficient adhesion of the primer to the steel?

These days a pro would use a 2K epoxy to begin I think?

Paging @Spencer or @Bellicose

[Bellicose 1,648]

Yep, epoxy first.

I'm assuming that's bog (too thick to be primer / paint layers). The way it's let go I'd say there was moisture trapped under the bog and it's just been sitting there patiently waiting to pop it's ugly head out and say hello. 

Do you have any pic's of other "suspect" spots?

[Spencer 20,930]

Yeah looks like what happens when you bog on bare steel and its gets moisture in it, or you leave a car sitting around with 1k etch or high build primers I have seen similar things. Just general failure of whatever paint system/methods were used on the respray. Epoxy for life when you fix it.

[markw 50]

Thanks for the insight @Bellicose @Spencer& @Nominal. I'll take a picture of the bonnet where paint has lifted off pretty clean on a large flat patch.

[markw 50]

Would you recommend I strip back these panels to bare metal again? @Spencer@Bellicose

[Spencer 20,930]

Um yeah man something went horribly wrong with that original paint job. Could be anything but as said above it could have had some contamination on the steel, sat around in 1k primer/bog and absorbed moisture etc. I would want to take all that off and get some 2k epoxy primer down to seal it up for good.

[Bellicose 1,648]

The thickness of that "paint" looks insufficient to be bog, it may be one of those 'spray bogs'. Most of the time the whole car would get done in it which unfortunately means stripping the whole car.

This Alfa was done in it and i had to get rid of the lot.

 

[markw 50]

@Bellicose that does look similar to what I am seeing. Interestingly the roof looks in very good condition. Bog seems unnecessary for most of the places I am finding it.

[tortron 48,937]

some "pros" used to  (and some still do) just spray the whole lot and sand to shape. i guess they figure its easier than hammering the few trouble spots, i.e ive mixed this paint already may as well use it/

[markw 50]

@Bellicose @tortron i take it the best route to removing this bog layer is by sanding it down? If you have any tips, let me know.

[tortron 48,937]

wire cup brush on a grinder would be my go to

[Evan 4,480]

12 minutes ago, markw said:

@Bellicose @tortron i take it the best route to removing this bog layer is by sanding it down? If you have any tips, let me know.

Nylon strip discs - don’t put them on an angle grinder as it will spin them too fast and put too much heat into the panel, put it on a variable speed polisher so you can turn the rotating speed right down - it still removes the paint/bog but minimises heat (which warps panels). One disc will also last ages also.

these things are what you’re after:

https://www.supercheapauto.co.nz/p/toolpro-toolpro-car-polisher-180mm/558317.html#q=Polisher&start=20&sz=60

https://www.mitre10.co.nz/shop/3m-clean-and-strip-disc-178mm-purple/p/265294

[tortron 48,937]

never had an issue with using them on a grinder. even on big long panels. 

[Evan 4,480]

I’m sure it’s possible, I’ve only ever run those discs on a polisher and it works well.