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Author Topic: paint cracking  (Read 2974 times)

dan

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paint cracking
« on: June 18, 2008, 08:06:21 PM »

HELP!!!
i have spent 3 solid weeks preparing my latest boat for painting, now after applying the top coat on top off the primer, the paint has started cracking as it drys, now theres big clusters of cracks everywhere  :embarrassed: what am i doing wrong and how can i solve it ???  :(
cheers
Dan
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Stavros

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Re: paint cracking
« Reply #1 on: June 18, 2008, 11:53:03 PM »

Right then what I want to know is simply what make of primer have you used and what is the top coat.It soundsto me as if you have used an Enamel primer and a cellulose or acrylic topcoat and this has caused a chemical reaction.


CURE   sorry to say it but rub all the paint off to bare wood or plastic and start again using all the same make of paint


Stavros
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dan

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Re: paint cracking
« Reply #2 on: June 19, 2008, 09:13:09 AM »

thanks Stavros,
i used halfords primer and one of their matalic paints, ive never had any problem in the past :(
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colin-stevens

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Re: paint cracking
« Reply #3 on: June 19, 2008, 11:58:31 AM »

silly question but had you washed the parts down? how thick had you laid the paint on? and how long between coats. you probably have no cure but to rub it ALL off. once it goes wrong, thats it. been there done that.
much sympathy
colin
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dan

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Re: paint cracking
« Reply #4 on: June 19, 2008, 02:11:28 PM »

i had sanded the primer then washed it and left it to dry for about 24 hurs, it had only one coat, im starting to think i put too much on too quickly :embarrassed:
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Martin [Admin]

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Re: paint cracking
« Reply #5 on: June 19, 2008, 03:51:42 PM »


Worse / best case of paint cracking I've ever seen...... never did find out if it was intentional or not...... ???
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Stavros

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Re: paint cracking
« Reply #6 on: June 19, 2008, 07:12:24 PM »

Those pictures that you have posted with the paint effect i believe is 100% correct this is a paint that is known a wrinkle effect and is available in a variety of colours.From Memory it is a 3 or 4 stage paint that you apply a special primer followed by a special base,overcoated by another base followed by lacquer.What baisically happens with this effect is that a chemical reaction occures between all the layers to cause what they call scratch opening thus revealing the colour layer underneath giving the crazed effect.There is an aerosol of wrinkle finish paint for car Dash boards which was on MG B's which has a similar effect.looks dammed good when done right.



Stavros
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Colin Bishop

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Re: paint cracking
« Reply #7 on: June 19, 2008, 07:15:05 PM »

Is the technical term "distressed"?
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Stavros

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Re: paint cracking
« Reply #8 on: June 19, 2008, 07:28:13 PM »

YUP it is Colin


Stavros
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JayDee

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Re: paint cracking
« Reply #9 on: June 19, 2008, 09:43:25 PM »


NO WAY !!!.
That is Crocodile Skin

John. O0  O0  O0
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Colin Bishop

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Re: paint cracking
« Reply #10 on: June 19, 2008, 09:46:45 PM »

Oh God! Jimmy Nail! Crocodile shooooooooes! (with motors)
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dan

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Re: paint cracking
« Reply #11 on: June 19, 2008, 11:13:34 PM »

that looks pritty good  O0, but mine are all in small patches on the one side
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Stavros

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Re: paint cracking
« Reply #12 on: June 19, 2008, 11:29:26 PM »

any chance of piccies especially the aerosols used


Stavros
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tigertiger

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Re: paint cracking
« Reply #13 on: June 20, 2008, 01:40:55 AM »


NO WAY !!!.
That is Crocodile Skin

John. O0  O0  O0

Or is it a 'Gator' boat?
I am being serious here BTW.
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Bunkerbarge

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Re: paint cracking
« Reply #14 on: June 20, 2008, 07:37:52 AM »

Paint designed to react like that was popular in motorcycle custom graphics, particularly in the '70's.  I think it was called crackelure, or something like that.  I'm sure Stavros will have come across it.  It never was my sort of thing!

I've also seen it in a paint system for furniture, designed to make the particular piece look a lot older than it really is.

As Stavros suggests though he needs all the information possible to be able to determine what went wrong.  A description of every step of the way would be usefull as well as every detail of the process used.  If the paints are compatable then it must be something to do with the process.  My first instinct would be condensation caused by moving the model from a colder temperature to a warmler one for the painting when a fine moisture film can form on the surface before the top coat is applied.

As has been said though, the only solution is to remove the lot irrespectiove of how it happened.
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Stavros

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Re: paint cracking
« Reply #15 on: June 20, 2008, 07:51:32 PM »

As bunkerbarge has said we could do with seeing the cans.There is more than one reason for this to happen and Bunkerbarge has highlighted one of them,another is primer coats been applied to thick or too fast,what I mean by that is simply one coat after another and not enough time for the thinners to evaporate causing solvent trap,then you apply top coat thinners in this will attack primer and cause shrinkage which can look to the untrained eye as cracking.Another old fav is the fingers,yes those wonderfull things which harbour all kinds of nasties.One should ALLWAYS dea grease with a proprietary solvent or wipes and strictly speaking wear latex gloves,hey I admit I don't do that BUT I will not handle a model or whatever after it's been degreased.
Another reason for paint cracking is dissimilar products.
Lets us see what you have used



Stavros
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dan

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Re: paint cracking
« Reply #16 on: June 23, 2008, 10:45:25 PM »

thanks guys, i think what i had done wrong, was after washing down the boat before painting i put a hair dryer on the boat to try and make the water dry quicker, as soon as it "looked" dried i started spraying it, soon after that the cracking appeared. anyway its all sorted now an the pain job looks really good if i do say so my self ;D, once the electrics are all securely in place i will be selling it

cheers,

Dan
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DickyD

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Re: paint cracking
« Reply #17 on: June 24, 2008, 08:03:50 AM »

That was quick Dan, what did you do to fix it ?
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dan

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Re: paint cracking
« Reply #18 on: June 24, 2008, 08:45:50 PM »

some people might say i cheated but it worked perfectly for me ;D because there were several coats of primer on the paint had built up a couple of mm on the hull so once it did crack it cracked all the way down to the fiberglass hull, so the cracks were pretty deep. i spent a couple of hours (about four all together) sanding down the damaged areas with different grades of wet and dry and it wasn't working so in the end i used p38 car filler to fill in the cracks, followed by some more sanding which worked perfectly then i went through the process of primering and painting it. it will be at my local lake tomorrow to see how it performs and looks on the water.

regards

dan
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DickyD

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Re: paint cracking
« Reply #19 on: June 24, 2008, 08:50:14 PM »

We'll expect photos then.  ;)
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dan

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Re: paint cracking
« Reply #20 on: June 24, 2008, 09:09:26 PM »

urrmmmm i got the photos before i painted it and after but not during the cracking i should have done though.
these pictures are of the final paint job, a metallic blue blending into a metallic silver


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