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jobrien389 Alfasud
Joined: 19 Mar 2003 Posts: 39 Location: DEVON
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Posted: Tue May 20, 2003 1:59 pm Post subject: how to repair stone chip/rust bubbles |
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Hi,Im learning about repairing stone chips , blemishes , rusty patches on body and looking for a bit of advice
I am sorting out some anoying blemishes on my bodywork left by previous owner. a few little bits of rust comming through on trhe boot lid next to the 1.7/33 badge. these were painted over with stark white toutch up which looks terrible and is not same white or blended back in.. so hate that. my 33 is white. real clean bodywork apart from these niggly bits to sort out which spoil polish-ability )
I have sanded off the affected toutchup paint (and carefully removed over spill from careless touchup painting going onto some surrounding original paint work) from affected area (about 3mm wide by 30mm long) because of the rust comming though I have taken it back to bear metal in places in this small area using 400grit wetdry.
Heres a tip----use a paper whole punch and punch a few time in the sheet of wetdry sand paper. then glue these small circles onto pencils with rubbers on them - makes a neat tool. also mask off surrounding area not to be affected to avoid silly errors etc.
Anyway... having removed eyesaw rust-paint-overpaint bubbles , taken it back to metal at lowest point. I am not totally sure of the correct procedure to build the paint back up. >? I coted the bear metal with cure rust for the moment to prevent oxcidation of the surface.
<things you may be able to advise on>
should I remove the cure rust or paint primer directly ontop?
does one use grey primer or white primer?
Should I use a filler paint to bring the level up a bit or should I just build it up with top coat paint (matched to car of course)
Are there any stages in between this i need to do? wetdry 1000 then 2000-polishing compound -polishing etc that kind of stuff
whats the process for creating a seamless repair.
thanks if you can help.
Jonathan _________________ 1.7 33 owner |
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Matt Stolton Alfa Sprint
Joined: 14 Mar 2003 Posts: 233 Location: London
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Posted: Tue May 20, 2003 10:39 pm Post subject: I'm doing the same now.... |
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White primer definetly. When you bring the top coat back a little with 2000 grit or rubbing compound, you don't want to rub through to a grey under layer....
If all the metal is nice and silver, with no brown or oxidised traces, normal priming should be OK. Remember, you can always sand down too much filler/primer. I found success with using a filling/high build primer (it was yellow in colour, but it got very covered anyway) This is good to give you a nice surface to work on with the proper primer. I virtually sanded the high build primer back to bare metal, to give me a really good base to work on. Then a couple of coats of proper primer, with a fine sand imbetween (1200 grit). Then about 3 or 4 THIN coats of topcoat, with a 2000 grit rub imbetween.
You are better off using lots of thin coats of the upper layers, and slowly gently rubbing down between each layer. This will later give you the really smooth finish you want. To finish the top coat, either really gentle 2000 grit (which must be properly wet), or even better, proper rubbing compound. With a dolop of good liquid wax after, wonders are achievable.
One really good tip is to use lots of water when rubbing down. I know alfas and water don't really mix, especially when lacking in paint protection, but to do a good job, the wet'n'dry must be very wet. I also used a little washing up liquid in the water to help everything glide smoothly, and to keep and paint in the water, not on the paper.
Another useful tip is to spray primer to meet the feather edge of the surrounding paint, but overspray the new top coat a little. With time and gentle 2000 grit (and lots of water),and perhaps a little more spray of top coat, a perfect seamless finish is possible.
Overall, the finish you achieve is about time, and not necessarily effort. The more gentle sanding you do will be rewarded. Doing a good job is time consuming I'm afraid, but will be worth it. _________________ Regards
Matt
Ex Alfa 33 'GTA' (P4 with Knobs On)
Now cruising in a 166 3.2 Ti!! |
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alexj Alfasud
Joined: 25 Mar 2003 Posts: 66 Location: New Zealand
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Posted: Wed May 21, 2003 2:20 pm Post subject: |
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For anti-rust paint you should investigate POR-15:
http://www.por15.com/
Regards
Lex |
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jobrien389 Alfasud
Joined: 19 Mar 2003 Posts: 39 Location: DEVON
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Posted: Wed May 21, 2003 2:47 pm Post subject: thanks |
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thanks for both advice tips. !
white primer then am going to change grey back at shop - who didnt really have much of a clue - they just sold stuff.
and looking at your por15 link i just found a great link www.frost.co.uk for all automotive restoration needs for us in the UK
jonathan. _________________ 1.7 33 owner |
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Marcin Alfa Sprint
Joined: 13 Mar 2003 Posts: 117 Location: Amsterdam
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Posted: Thu May 22, 2003 9:28 am Post subject: |
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Hi,
few months ago I discovered zinc-spray, you can buy it probably at every do-it-yourself store. I think it's very usefull for protecting bare metal surfaces against rust. It dries almost instantly and forms an elastic and conducting layer that prevents rust forming, which you can finish off the way guys described above. Series 3 33 have the whole body galvanised and are less rust sensitive, so I think it's worth trying.
Good luck,
Marcin |
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jobrien389 Alfasud
Joined: 19 Mar 2003 Posts: 39 Location: DEVON
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Posted: Thu May 22, 2003 11:09 am Post subject: primer colour |
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I was thinking if i use grey primer then at least i'll be able to see if I have sucesfully covered all the primer with white. that way ill know if I have rubbed a layer too far back. white primer you wont know. i just keen to get it right.
for the polishing compound (after wet n dry process) do you use something like Farecia G-Matt ("ensuring a good base for coats of paint") G3 paste, G10 Liquid compound ("fine cutting action"), Top Glaze ("use to finish off paintwork giving a high gloss finish" ) all this is a bit confusing
any further comments suggestions.
jonathan _________________ 1.7 33 owner |
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Gary UK Alfa Sprint
Joined: 17 Mar 2003 Posts: 218 Location: Darlington UK
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Posted: Thu May 22, 2003 11:35 pm Post subject: |
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Use the same coloured primer as is used on the car.
Luckily white is the easiest colour to patch in but I have always found that patches never blend in well. Id spray the whole panel area up to some point like a trim stripe or a contour where the light catches it differently i.e. on the boot where the badge is I'd spray the whole flat area and blend it on the top 90 degree bend (where you go from perpendicular to horizontal). Because the light effects the look of the colour on an angle it hides the blending point. Use colour matched base coat and the type of lacquer that needs a seperate hardner added before using, it's loads harder (it will last about 24hrs once put in a spray can) DON'T use a one coat paint, it's crap.
Spray the base coat just on the area you are doing (rub down the join till flat when dry) but feather the lacquer over the edge of the new base coat then cut it with some T Cut(or similar) till the whole new lacquer is smooth and shiny.
Honestly you will NOT get a good finish doing a small patch, it will stick out a mile as you will not get the filler flush with the existing paint.
Tip - put the aerosol in a bucket of hot water before using it.
If you do the above you will get a really good finish |
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jobrien389 Alfasud
Joined: 19 Mar 2003 Posts: 39 Location: DEVON
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Posted: Fri May 23, 2003 1:10 pm Post subject: thanks |
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thanks gary and matt and others for advice on process. great help to me that all clarified. .I will attempt a local area touch up.. see how it goes. but i think i may do a larger area at a later date (may have to hire some propper spray gun to do it.. may even practice on a old panel from the scrappy. then commit to my car boot up to the fold in the boot as there are a few crappy touch ups from prev owner and am never going to get it perfect doing them individually as you suggest.
have got to sort out localised rusting in places where rear lights are (again touched up with delux or something!!) take lights out and rub it back probbs need to get filler out.
am filling missing chunk in corner of the foam based spoiler - been building the profile up over several days, but dont know if its going to work to bond propperly around edges may get crack appearing. doh. so may need some other sort of bonding stuff round edges
with some leftover filla I proceeded to fill the worn out bit on my young brothers skateboard kick ;o) (he wasna impressed with my filling effort on his skateboard. funny! ) _________________ 1.7 33 owner |
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Gary UK Alfa Sprint
Joined: 17 Mar 2003 Posts: 218 Location: Darlington UK
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Posted: Fri May 23, 2003 7:02 pm Post subject: |
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You can get proper paint put into spay cans at most automotive paint suppliers, cheaper and easier then hiring equipment (and you can get an excellent finish with it). |
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