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  #16 (permalink)  
Old 12-29-2009, 07:31 AM
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Quote:
Originally Posted by cutterbond
I was thinking about switching to it, because K36 takes so long to cure.
Are you in a production shop? Why do you need primer to cure so fast? K36 is far superior to any polyester primer there is.

Vince

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  #17 (permalink)  
Old 12-29-2009, 07:37 AM
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Nason 2k is a pretty good primer ,can you dent the primer with your fingernail? if its balling up it might not have enough hardner in it.try wiping lacquer thinner on it if it comes off, thats the problem ,if its cured it wont bother it at all....if its not cured you got to get it off and redo it.Its a beech ,I know first hand but its the only way........I learned this trick from an old timer it works great for curves.....Take a full sleeve of wet sand paper and get it very wet in a bucket of water......fold the whole wad in half or thirds down the long way,it'll be about an inch thick,the paper itself is the block, start wet sanding ...it'll be stiff enough and flexable enough to do a great job.sand in a circular motion (just on the curves) then as the paper wears down just peel a piece off and keep going....this is also a great way to sand clear....
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Old 12-29-2009, 07:43 AM
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Quote:
Originally Posted by deadbodyman
Nason 2k is a pretty good primer ,can you dent the primer with your fingernail? if its balling up it might not have enough hardner in it.try wiping lacquer thinner on it if it comes off, thats the problem ,if its cured it wont bother it at all....if its not cured you got to get it off and redo it.Its a beech ,I know first hand but its the only way........I learned this trick from an old timer it works great for curves.....Take a full sleeve of wet sand paper and get it very wet in a bucket of water......fold the whole wad in half or thirds down the long way,it'll be about an inch thick,the paper itself is the block, start wet sanding ...it'll be stiff enough and flexable enough to do a great job.sand in a circular motion (just on the curves) then as the paper wears down just peel a piece off and keep going....this is also a great way to sand clear....
Thanks for the tips on testing the paint--it's really been weighing on my mind. Can't dent it with my nail. I'm going to go out and buy some laquer thinner later and run that test too.

If I have to take it off and redo it, I may just lay under the tires and have my wife run me over a few times instead.

So many interesting ideas for working those curves--I'm looking forward to trying them. That area of the truck is right at eye level and of course it's the hardest place to get right. Murphy's law...
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Old 12-29-2009, 07:51 AM
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Quote:
Originally Posted by wyomingclimber
Thanks for the tips on testing the paint--it's really been weighing on my mind. Can't dent it with my nail. I'm going to go out and buy some laquer thinner later and run that test too.

If I have to take it off and redo it, I may just lay under the tires and have my wife run me over a few times instead.

So many interesting ideas for working those curves--I'm looking forward to trying them. That area of the truck is right at eye level and of course it's the hardest place to get right. Murphy's law...
I have to warn you though, not all 2K primer is created equal! There are 2K products out there that even when mixed properly AREN'T insoluable to lacquer thinner! So just because it may soften up with the lacquer thinner rub test it doesn't mean that it isn't "performing". It may not be performing as well as some other primer, but it maybe doing just as the manufacturer expected.

Brian
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  #20 (permalink)  
Old 12-29-2009, 09:14 AM
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Nason 2k is the primer I was talking about. I forgot to catalyze a 2k primer twice when feather fill first came out I was used to lacquer primer (industry standard) at the time.so i know your pain. I wouldn't think its the problem if its not soft. BUT.. I am the local expert around here at removing un catalyzed primers and paints (the last time I mixed clear and wasnt paying attention I mixed a 1:1 clear at 4;1) and pretty much fixing any kind of screw up...every time I think I've screwed everything up there is and cant possibly screw anything else up ,I amaze myself....seriously though If you need to get it off I can help make it easier,lets hope thats not the case.Can you gouge the primer out with your finger nail?
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Old 12-29-2009, 11:58 PM
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Quote:
Originally Posted by deadbodyman
Can you gouge the primer out with your finger nail?
No way. I pushed my thumb nail as hard as I could into it and it didn't make a mark I could feel running my finger over it. Gonna try the lacquer test tomorrow.

I honestly don't know why there would be a problem. I'm sure I catalyzed it. In fact, my problem seemed to be the opposite. I had to strip it all off the box because of dry spray.
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  #22 (permalink)  
Old 12-30-2009, 06:44 AM
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It sounds like its hardened to me.I dont know why it would roll and clog the paper,unless you used the wrong reducer or hardner by mistake. I've done that too,I had to check all the levels of all my hardners. What grit paper are you sanding with? wet or dry?do you have any other paint materials on the same bench as the primer? One more thing... 180 and finer grits get packed with powder pretty quick, You have to slap the pad with a paint paddle or something to loosen it up and clean the paper when you dry sand , wet sanding works better. in my opinion. also if you lay down your guide coat to thick it;ll roll too but its the guide coat rolling not the primer.If it sounds like I've made a lot of mistakes in my life as a body & paint man, your right I have, No need for you to too.try a few of these ideas and let us know.I cant have made every screw up..but these are some of the ones I remember.

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  #23 (permalink)  
Old 12-30-2009, 10:00 AM
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Quote:
Originally Posted by deadbodyman
180 and finer grits get packed with powder pretty quick, You have to slap the pad with a paint paddle or something to loosen it up and clean the paper when you dry sand.
Maybe that's my problem--I'm using 220. It gets packed up in a solid mass and I have to hit the sandpaper with the compressor to get it off. I'm sure I used the right hardener--I'm way too absent minded to allow anything but the stuff I'm currently using to be anywhere within my line of sight.

Quote:
Originally Posted by deadbodyman
If it sounds like I've made a lot of mistakes in my life as a body & paint man, your right I have, No need for you to too.try a few of these ideas and let us know.I cant have made every screw up..but these are some of the ones I remember.
I hear you. I figure if I did this again, I could do it in 1/3 the time for 1/2 the money. I didn't even know how to check my oil when I started this project. If it wasn't for this board, I'd still be staring at a 10 foot high pile of rusted parts.

I'm looking forward to trying all the techniques suggest. I'm praying I don't have to resort to your wet sanding idea, though. I think there would be ice floating in my bucket this morning...
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Old 12-30-2009, 08:44 PM
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IF all else fails, an old pirate's trick:

(you will need 6" stick-it DA paper, Saran Wrap, spray-can Styrofoam home insulation)

1. cut 8 1.5" pie shaped slices around the paper, should leave a 3" sun and 8 rays, save the clippings
2. place paper over a coffee cup of hot water, the stream will let the paper go limp
3. place paper, grit up, where you wish to work, start at center and layout flat, install clippings into slots. Make it pretty, style points count
4. cover area with Saran-Wrap, no wrinkles.
5. apply Styrofoam to cover paper size and allow to cure
6. trim sanding block to fit your hand but slightly larger than the paper
7. install new paper grit down and attach sanding block, check for perfect contact, the slots leave somewhere for the dust to flow.
8. go to town with your brand new, PERFECTLY sized and shaped sanding block. These only work for a small area thanks to constantly changing curves, you will see and fell the limit instantly.

Guide coat is your friend, patience is a virtue and Happy New Year.
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Old 12-30-2009, 08:52 PM
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My God, that sounds harder than building the thing!

I found some interesting sanding pads at Ace. Three in a pack and they can be stacked kind of like your wet sandpaper concept in order to give them a little stiffness.

I think (hope) they might do the trick, working in small areas at a time w/some guidecoat.

It's just one of those scary things because you aren't really gonna know til you get the paint on it and it's too late...
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  #26 (permalink)  
Old 12-30-2009, 09:00 PM
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Hymmm ,spray styrofoam.....now you got my brain working I see lots of possibilities here ....WC everything sounds normal with your primer try wet sanding it'll be faster and easier. 320 - 400 oughta do it the water keeps the paper clean....
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Old 12-30-2009, 09:19 PM
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That wad of of wet paper is a great way to sand any curve.the water keeps the paper sucked right up to the work if you take your hand off and walk away the paper will still be stuck there when you get back.Old Willie showed me a lot of handy little tricks (RIP) Mean old coot ,but knew his stuff.I'll tell ya what though sanding a curved car is easier than a straight slab of steel...
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Old 12-30-2009, 10:03 PM
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"My God, that sounds harder than building the thing!"

not really, it takes longer to type it than do it. I stole that one from the guys at the boat shop but they do it reversed.

They took disc adhesive and glued a full sheet to the haul then cut a piece of hard Styrofoam foundation insulation and sanded that against the haul to make a sanding block, PERFECTLY sized with the paper. A real time saver on large areas. It will show when it's out of it's area by hitting in center or on the edges.

A bodyshop would only use this for odd shapes, multi-bevel door jam, roof ribs, style-lines on a pick-up bed, multi-grooved doors, VW fenders Anything that saves time is worth a look.
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Old 12-30-2009, 10:28 PM
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OBM,will sticky back paper stick to that spray foam without tearing the foam up when you replace the paper? I figure I can make forms out of wood or PVC and make some handy blocks with that stuff.
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Old 12-30-2009, 10:28 PM
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A tip would be to not change sand stoke direction in the same place twice ..

guide coat is indeed your friend
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