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Bob Warfield

Another Dupli-Color primer ?

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I ran out of my beloved Plasti Kote primer a week ago. After reading way too many threads on here I decided to try the Dupli-Color. Working on a 53 Ford, body was washed in warm soapy water after sanding with 600. I sprayed it in my 70* basement, 45 - 50% humidity and left in the dehydrator over night. This primer gums up my sandpaper just like the Testers enamel used to and just feels soft to me. I never had that problem with Plasti Kote. Anyone else experience this?

Thanks...Bob

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I only use Dupli Color on all I build. Grey and or white. Never had that issue. I use the Filler Primer version.

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Agreed. I did love Plasticote, but that ship sailed a long time ago for me.. probably 10 years. 

I have been near exclusively using Duplicolor since.. same as Ray. Not as foolproof as Plasticote was, but no real issues. The other primer I use is Tamiya but only under their painted.

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What specific primer are you having this problem with?

Duplicolor makes several, and they don't all behave exactly the same way.

There's also an unfortunate tendency to re-formulate rattlecan products to cheapen them lately...the last version of PlastiKote I tried being one such now-useless mess.

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2 hours ago, Ace-Garageguy said:

What specific primer are you having this problem with?

Duplicolor makes several, and they don't all behave exactly the same way.

There's also an unfortunate tendency to re-formulate rattlecan products to cheapen them lately...the last version of PlastiKote I tried being one such now-useless mess.

Bill, I first used the white, DAP 1689. I noticed I still had a few very minor scratches showing after sanding with 400 so I decided to try the scratch filler DAP 1700. Neither primer dried very hard as it gummed up my sandpaper. Last night I sprayed it with Testers flat black thinned with lacquer thinner and left it in the dehydrator over night. This morning the paint is nice and hard. I'm going to try some 1,000 paper on it in a bit and see what happens.

Thanks...Bob

 

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Hey, friend.... Just curious about something. Why are you doing so much sanding with such coarse sandpaper? You shouldn't need anything more than about 800-1200 to prep the plastic, unless you're doing major bodywork....... I block sand with 2000 before primer myself......

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40 minutes ago, JollySipper said:

Hey, friend.... Just curious about something. Why are you doing so much sanding with such coarse sandpaper? You shouldn't need anything more than about 800-1200 to prep the plastic, unless you're doing major bodywork....... I block sand with 2000 before primer myself......

Actually, most model car bodies are wavy as eff. I routinely block the waves out with 400 wet, then go up to 600 or 800 prior to primer to minimize scratch swelling.

On the areas that need no remedial work, my tried-and-true surface prep is a careful all-over scrub with hot water and a mild abrasive cleanser like "no scratch" Comet, using a toothbrush.

That gets all the little nooks scuffed...nooks that can allow paint to peel later, or pull away if left glossy...without softening details like sanding can.

The Comet-scrub also removes any of the dreaded "mold release", and if you're really anal, a wipedown with isopropyl alcohol is cheap insurance against fisheyes.

EDIT: Your paint looks good TJ, whatever you're doing, and that just proves there are lotsa ways to skin this particular cat.

I've turned out a few decent ones too...

Monogram 70 Chevelle SS - Model Building Questions and Answers - Model Cars  Magazine Forum

 

Edited by Ace-Garageguy

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37 minutes ago, JollySipper said:

Hey, friend.... Just curious about something. Why are you doing so much sanding with such coarse sandpaper? You shouldn't need anything more than about 800-1200 to prep the plastic, unless you're doing major bodywork....... I block sand with 2000 before primer myself......

I did do some filling with Evercoat glazing putty and the body was quite wavy as well.

Thanks...Bob  

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2 hours ago, Bob Warfield said:

Bill, I first used the white, DAP 1689. I noticed I still had a few very minor scratches showing after sanding with 400 so I decided to try the scratch filler DAP 1700. Neither primer dried very hard as it gummed up my sandpaper...

I'd suggest a coupla things...assuming Duplicolor hasn't changed the formula on their primers yet again.

I've had some similar "gumming" of the sandpaper over the years, but it can usually be minimized by allowing every coat of primer to flash off at least 10 full minutes between applications.

Another anti-gumming procedure that works exceptionally well, almost always, is to use waterproof sandpaper, wet. The water acts as a lubricant and helps to disperse sanding particles rather than allowing them to build up and clog the paper.

Unfortunately, there have been lotsa issues with automotive primers lately, and experimenting as you go these days is about the only way to insure good results.

 

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1 minute ago, Ace-Garageguy said:

I've had some similar "gumming" of the sandpaper over the years, but it can usually be minimized by allowing every coat of primer to flash off at least 10 full minutes between applications.

Bill that could very well have been the problem. I was used to the old Plasti Kote which was almost foolproof. I usually only waited until the gloss dries away and spray another coat. I'll give this a try.

Thanks...Bob

B.T.W. what kind of car is in this picture?

 

 

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8 hours ago, Painted Black said:

Same as Ray, never any problems with DC, except!! After spraying the nozzles continue to seep out primer. Makes a H of a mess.

Hmm, I've got probably 40 cans of Duplicolor primer, paint and clear in my shop at the moment.

Never had a single one seep in probably 20 years of using Duplicolor.

 

 

 

Steve

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You said you used a glazing putty under the primer, if I read correctly. Was it a single stage product, or the type that requires a catalyst mixed in? Some glazing putties from a tube can take quite a while to FULLY cure, even though the surface dries fairly quickly. I think you may have solvents from your putty slowing the dry of your primer.

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1 hour ago, bisc63 said:

You said you used a glazing putty under the primer, if I read correctly. Was it a single stage product, or the type that requires a catalyst mixed in? Some glazing putties from a tube can take quite a while to FULLY cure, even though the surface dries fairly quickly. I think you may have solvents from your putty slowing the dry of your primer.

Actually I used Evercoat Easy Sand which is a 2 part filler. I've used this filler for more than 20 years along with my trusted Pasche model H air brush. I've been retired for over 2 years now but before that I repaired fiberglass bathtubs full time for more than 20 years. Never had any trouble with the Evercoat.

Thanks...Bob 

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My first thought was one of those lacquer-based  putties from a tube. Yeah, the catalyzed stuff is fairly fool proof; I use it all the time at work. This one's a real head-scratcher!

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15 hours ago, StevenGuthmiller said:

Hmm, I've got probably 40 cans of Duplicolor primer, paint and clear in my shop at the moment.

Never had a single one seep in probably 20 years of using Duplicolor.

 

 

 

Steve

Hey Steve, this was just 5 minutes after using, I've had some where the bubbles go all the way to the rim.

DSCN5317.JPG.ee0cff71c6609eb7f67bebd3b3e281f1.JPG

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10 hours ago, Painted Black said:

Hey Steve, this was just 5 minutes after using, I've had some where the bubbles go all the way to the rim.

DSCN5317.JPG.ee0cff71c6609eb7f67bebd3b3e281f1.JPG

That is likely due to the metal pin in the nozzle not fully returning to its upper "off" position. When that happens, pull up on the trigger button on top to lift it off the metal pin, then using some pointy grabber (like needle-nose pliers or tweezers, slightly pull up on the metal pin. That should stop the slowly leaking paint and bubbles.

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I've switched to Tamiya primer almost exclusively. I have no problems and it works under all types of paints. I am looking for a good light/platinum grey and red primer, though.

Charlie Larkin

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2 hours ago, charlie8575 said:

I've switched to Tamiya primer almost exclusively. I have no problems and it works under all types of paints. I am looking for a good light/platinum grey and red primer, though.

Charlie Larkin

Tamiya red primer is as good as their other colors, but I hate paying $15/can for it.

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1 hour ago, Rodent said:

Tamiya red primer is as good as their other colors, but I hate paying $15/can for it.

I'm usually able to get it for around $10-11. I'm wondering if MCW's new primers will start coming in oxide and white? I'd give that a try, especially if I can get a reasonable amount at a good price.

Charlie Larkin

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