Murray_Calavera

I'm confused, so your saying after blowing the area off, the guide coat is gone. But then when you wipe it down, the guide coat residue becomes visible again? This isn't a trick question like there is guide coat residue on the rag that your wiping the area down with? I cant see how once something is removed, it comes back when cleaning with wax and grease removed?

I'm a bit confused by this post, so I'll address the bit I understand lol. Use an air compressor and blow away the guide coat sanding residue. All the better if you have a moisture trap for your compressor. You'd want to do this a few times as you sand the area, you wouldn't for example sand the entire area till you think its perfect and then 'confirm' that is it by blowing away the guide coat residue. Sand the area, blow away the guide coat residue, inspect the panel, back to sanding... rinse and repeat.

This sounds like a perfect excuse to install a Haltech R3.

Do I think this is worth fixing properly? Nope. I'd use this project car to practice skills you want to learn. Once you're happy with your new skill set, I'd move the car on to the next owner. However if you think it is worth fixing, there is only one scenario I can think of that it makes sense.... I don't know this platform so I can only guess, lets assume the roof attaches like this - Where the red lines are, that is the frame/body of the car. When the car was manufactured, we'll assume they spot welded it to those points on the body. If this is the case, you could drill out the spot welds, then weld on a replacement roof. It is reasonable to assume that with enough practice, you could spot weld the roof back on. If the roof doesn't attach like this, say its all one piece... your back to the original plan of a cut and paste job. I wouldn't attempt it. Only you can answer that one. We already know what the previous owner thought lol. You'll have to decide how important it is to you.

I know you'd like to believe that it won't spread, but it will. Just pretend that it wont. Give the roof a little pat and say she'll be right.... She'll be right

Nice, saves me ranting about how painful it is painting a roof with rattle cans lol. Personally, I wouldn't chase the rust back any further. What happens if your 30cm deep into your roof and still going? This is why I was suggesting fiberglass, the holes are quite large but easy to patch with fibreglass. There will be a million youtube videos of people doing this shonky job you can check out for a visual. Once the holes are patched with fibreglass, you can rebuild the corner with body filler (like the last guy did). Indeed, its a shit go

Yeah this can't be overstated, this job is crazy hard even for a professional.

With rattle cans? There's a reason why the last person did that repair. It's my advice for you as well, do as the last person did. Resist the temptation to go digging for rust, the hole you will be left with may wind up being so large that it's a nightmare to reform that corner of the roof.

Hmm makes things tricky then. I can't in good faith say, go forth my child and weld in whatever metal you remove in your quest for rust. I very strongly expect that adventure will end in sadness. But you can't leave the car as it is, you literally have a hole in the roof. Also, I know you think the rust doesn't go much further, but the more I look at those photos, I really think the rust does in fact go much much further. If you are 100% committed to being the only person working on the car.... stop where you are, hit it with rust converter, fiberglass, body filler, paint work, pretend you never discovered the rust in the first place? Even if the body was repaired, painting the roof is a pain. Were you planning to use rattle cans to paint the roof?

If your current chain of thought is, I'll go somewhere like pick and payless (or equivalent) and causally remove the bit of roof with your BYO grinder then casually weld that into your car... oof. It might sound easy but you will 100% end up with a warped roof. You say you'd prefer some ugly fab work, but I don't know if your prepared for how ugly this will be lol. I've seen professional welders do similar but easier repairs and still end up with warped panels. It is reasonable to assume that from your current skill level, you won't be able to do this cut and paste job while keeping flat panels. Ok, but we are here to learn. This might be the go... jump on car sales, sort by price, buy the cheapest thing with rego and drive it home. This is your new practice vehicle. If you're thinking of doing the cut and paste job, try it on this car. Cut out the panel (hey it's a perfect fit) weld in the panel. See what you think of the results. Next thing you could try, practice removing the entire roof in one piece by drilling out all the spot welds etc. Have a crack and welding the roof back on.

Ok, thats a good starting point. So before we start.... do you mind if the car say isn't a strong as it was before? My first thought is go excavating for rust. You'll be left with a gaping hole, that will be filled with fiberglass. You could make it look factory pretty easily but yeah, if you never crash it will never be an issue right? Before we look at other options, how confident are you welding?

All good, I'll tag myself in lol. What car are we looking at here? What is its value/sentimental value? What type of repair do you want to do, 100% perfect back to stock or are you happy just to have the rust gone? My initial thoughts are not very positive but I'll wait to see what your goals and thoughts are first before I start raining on anyone's parade.

Hasn't risen high enough on the to do this yet for it to be done lol. One day it will be done... one day... I know, but I tell myself its ok because I took a heap of temp measurements of the terminals over a 12 or so hour drive, temps were never an issue. Plus I made sure to pat the bulk head and say "she'll be right". So, yep she'll be right lol.

Those Efi bulkhead terminals have been in the car for about a year now, they are perfect. So, upgraded wiring, relay mod, uprated terminals and you can run that pump flat out all the time no issues.

Have a read of this -

It happens, that's what your single stage filler is used for. If it is still visible after the 3 coats of 2k primer, it will be visible after the paint is laid down. Its hard to give 100% perfect advice without being there in person, I'm very tempted to say stop where you are, fill your pin holes with a single stage putty first then keep going.

My first thought is to use something like this https://www.bunnings.com.au/goof-off-177ml-adhesive-remover_p1580913

You beat me to it, I was going to say this - And this - Sounds like things are coming along pretty well and your learning heaps along the way.

@RA708 All good mate. Once you get your first car and can get hands on, that's when you'll really start to learn. There are a million channels worth watching on youtube, but I'd like to make a recommendation. Check out the project binky series. Just a little bit of modding happening there, I think you'll find it interesting https://www.youtube.com/@BadObsessionMotorsport

Not trying to be rude here, I'm guessing your currently not old enough to drive yet? If this is the case, I'd stick with just watching stuff on youtube. If you find the right channels you can actually learn quite a bit there.

What are you planning to do specifically? I would be very surprised if you need to learn any math for these 'few builds' you have planned for the future.

Sounds good. Might be worth double checking what size rim the tyres you are running want. Generally I'd expect to see a 235 tyre on a 8.5 rim. Any possibility of an easy to source OEM 9.5 wide rim? Also with the thoughts of the square setup, I'd still say wider is going to be better. Say your currently on 235 front and 255 rear. Going to square 255 will be better. But say you could fit, 255 front and 275 rear, that will be better again. In hypothetical land there might be a world where you go so wide that performance starts to go backwards, but I don't think you'll ever bump into that situation in real life.

I would be very surprised if you could tell the difference between 8kg and 12kg wheels in a blind A B test. What you will be able to notice is going to wider wheels (+wider tyres). If you don't have to abide by any rules, I'd fit the widest wheels you can get under the guards.

What type of track driving will you be doing? Do you have a set of class rules you need to abide by that will limit your rim / tyre width?

Oh I probably didn't speak enough about the small sanding block for blocking large areas. In the video about 3 minutes in, he talks about creating valleys in the panel. This is the issue with using a small sanding block for a large area, it's way too easy to create the valleys he is talking about. With a large block its much easier to create a nice flat surface. Hard to explain but in practice you'll notice the difference straight away using the large block.