paint reaction problem rears its head again

[Rubce]

Hi All

For those of you who followed my car painting experiences last year you will remember that I had a problem with the basecoat reacting on the bootlid. After several attempts I finally admitted defeat and ripped the lid back down to bare metal and restarted the filling and priming process. It then sat in a primed condition in the guest bedroom for the past 6 months. At the weekend I dug it out, and applied the basecoat and laquer. Success, no reactions this timeand its now fitted to the car

HOWEVER, a few weeks ago I cast my eye over the bonnet which was also in the same bedroom. I decided I was unhappy with the finish so sanded the laquer and a large portion of the basecoat back off. I intended the respray the bonnet at the same time as the bootlid. Up to this point the bonnet had not suffered any reaction issues when sprayed last year. Well b**ger me, it reacted this time after the application of the first coat of fresh basecoat. WHY???!!!!!!:XAll I had done was sand it back, wipe over with panel wipe, leave to dry, mask off and then spray. GRRRRR

I am tempted to cut my losses and rip the outer faceof the sodding bonnet back to bare metal again and repeat seeing as that worked well with the bootlid.:shock:

On a positive note, my spraying technique has improved leaps and bounds over the past 18 months. The finish I achieved on the bootlid is in a different league to that which I produced on the bonnet last year.

Bruce (frustrated)

[martin]

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If you look back through this subject, you'll find there was a lot of knowledgable advice about NOT using 2 pack - difficult to avoid this - told you so !

[jamcarr2]

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Hi Bruce (frustrated)

If there is any lacquer what so ever left on the bonnet it will react as soon as the base coat hits it

JOHN

[Rubce]

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Martin

Paint reaction problems affect cellulose as well so your point is pointless.

Bruce

[Rubce]

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jamcarr2 wrote:

Hi Bruce (frustrated)

If there is any lacquer what so ever left on the bonnet it will react as soon as the base coat hits it

JOHN

Hi John

I was not aware of that:shock:. Yes there could be a small amount of laquer remaining in the affected areas. I will take it all back down to just the primer and try again.

Your statement puzzles me as I did several of the panels last year one side at a time. How come the basecoat on the second sidedid not react with the laquer on the first side along the edge where they meet?

Out of interest how is a damaged panel repaintedif the basecoat reacts with the laquer?

One of the things I have enjoyed so much about doing therestoration is all the new things I have learned and continue to learn along the way.

Regards

Bruce

[m9fdb]

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2k base shouldn’t react over lacquer in my experience - I always wipe the panel wipe on and off with another rag in the other hand though (wax on - wax off style )as even though it does evaporate you still get particles of it left.

There are so many things that can cause reaction though Bruce - so to be sure I would either bare metal the bonnet again as you suggested of 320 grit it back to the primer and then 800 wet flat it before spraying it again ....

[deanoed]

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you can give it a coat of isolator it wont react after that

[marshman]

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martin wrote:

If you look back through this subject, you'll find there was a lot of knowledgable advice about NOT using 2 pack - difficult to avoid this - told you so !

Not helpful to Bruce. IIRC there was also at least a similar amount "of knowledgeable advice" who said use 2 pack - I've done cars with both types at home, both 2 pack and cellulose have problems but all things consideredI would use 2 pack everytime.

Bruce,

The safest option is to go back to bare metal. An isolator coat still won't gaurantee no reactions.

On the plus side you did say your technique had improved and the finish was now better so you will end up with a superb finish on the bonnet.

Good luck

roger

[801802971]

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Getting my Stag resprayed sometime and 2 pack was recommended to me by my neighbour who has a coachwork business and will be doing the respray.

One question I have is, how many coats do people recommend of primer, colour and laquer?

Any advice would be appreciated.

[marshman]

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Hi 801802971, (do you have a name?)

Iwould let the guy doing the spraying decide. Its a bit like asking how long is a piece of string. There are so many factors. What state is the paint in now, are you changing the colour, what colour are you spraying it, how good a finish do you want, how much do you want to spend. Tell him clearly what you expect in terms of prep work and final finish - i.e. bare metal, remove all rust and dents or just a quick paint job to smarten the car up?Do you want a concours finish?and agree a budget.

I have sprayed cars and stood back and don't like what I see and given it a few more coats to get the colour depth right.I was watching Chop Shop on Discovery last night (its a car programme - nothing to do with lamb or pork) they were spraying an old Cheverolet in pale yellow. the spray shop hated it because to colour (color - American!) was thin - i.e. it didn't cover very well. They ended up giving 15 coats just of the colour!

All IMHO of course

Roger

[801802971]

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Sorry Roger,

Very bad manners on my part, I am Jim.

Many thanks for the reply, very logical and much appreciated.

Jim

[Rubce]

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Hi Guys

With the exception of Martin's all your postings have been very helpful. Taking them all on board I think I will go for the back to bare metal approach as that worked well with the bootlid.

Once the bonnet is done thats the car complete with regards to spraying. If and when I ever spray another car I will usebasecoat and laquer again or maybe try just sttraight forwarrd 2k.

Cheers

Bruce

[stag estate man]

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Rubce wrote:

Hi Guys

With the exception of Martin's all your postings have been very helpful. Taking them all on board I think I will go for the back to bare metal approach as that worked well with the bootlid.

Once the bonnet is done thats the car complete with regards to spraying. If and when I ever spray another car I will usebasecoat and laquer again or maybe try just sttraight forwarrd 2k.

Cheers

Bruce

hi bruce
just out of interest why are you using laquer on a flat colour i thought only base coat paints such as micas and metalics used a laquer
grahame

[Rubce]

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Grahame

Basecoat is designed to be used with a laquer. It has no shine until the laquer is applied. Basecoat is different to 2k single coat.

See attached link.

http://auto-paint.co.uk/carpaint/ind...p;productId=87

Cheers

Bruce

[stag estate man]

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hi bruce
i get all my paint here but i tend to use cellulose although i have used 2 pack with a air fed mask. all my colours are flat colours and do not need a laquer. is the colour you are using a metalic finish then?

cheers grahame