How to prime greasy plastic from kitty hawk and trumpeter

[Chuck4]

When I try to use tamiya white or gray primer on trumpeter or kitty hawk plastic, the primer seems to bead up, or at least sheen off of some spots. This doesn't happen with other makes like hasagawa, or revel. I've washed the plastic in soapy water, and even washed it with gunzy Sanyo thinner. But to no avail.

What primer do you use with trumpeter or kitty hawk?

[scapilot]

Try a real light sanding with 1200 grit paper to give the primer something to stick to.

[TXCajun]

You know, something else you could try is using a soft toothbrush and comet cleanser or toothpaste to give the surface a little bite. Alternatively, you might try using extra-fine furniture grade steel wool (for polishing out poly coats). What you obviously don't want to do is be too aggressive and knock down or soften detail you've worked hard to preserve.

I've used Tamiya primer as well and I like that it is lacquer based. Thus, it "should" bite better. You might also want to check out Floquil Railroad gray primer. Before Tamiya and Mr. Surfacer came along, it was the standard for a good lacquer-based primer. The original bottle is tough to come by, but here is their spray: http://www.amazon.com/Floquil-Railroad-Enamel-Paint-Primer/dp/B0069FM0QC

I've also used Krylon primer with success. Decant it and spray with your airbrush.

Cheers,

TX Cajun

[toadwbg]

Good advice above.

I used Tamiya Lacquer Primer in a rattle can on my last Trumpeter build and it turned out great.

[dmthamade]

When I try to use tamiya white or gray primer on trumpeter or kitty hawk plastic, the primer seems to bead up, or at least sheen off of some spots. This doesn't happen with other makes like hasagawa, or revel. I've washed the plastic in soapy water, and even washed it with gunzy Sanyo thinner. But to no avail.

What primer do you use with trumpeter or kitty hawk?

Funny you should be having this problem... I'm doing a 1/32 Trumpeter Harrier+ for a group build and can't get paint to stick to the fuselage. I've done lots of Trumpeter kits in the past with one kit not being able to be glued together. Primer i use is Tamiya spray but it didn't hold. Damnest thing... prepped this thing as normal and the paint doesn't stick. Only the main fuselage halves as they are their own sprue. I also note that one seam is a little weak, too.

Don

[lesthegringo]

Funny you should be having this problem... I'm doing a 1/32 Trumpeter Harrier+ for a group build and can't get paint to stick to the fuselage. I've done lots of Trumpeter kits in the past with one kit not being able to be glued together. Primer i use is Tamiya spray but it didn't hold. Damnest thing... prepped this thing as normal and the paint doesn't stick. Only the main fuselage halves as they are their own sprue. I also note that one seam is a little weak, too.

Don

I had the misfortune to have to strip an F-15 I was building, as the darker grey that I was using seemed to come out very sandy and rough. As a attempt to get it to flow out a bit better, I had added a very small amount of Ace Hardware Lacquer (cellulose) thinners to the paint as well as some white spirit; the idea was that it would re-liquify the paint and smooth it out. Well, it didn't work, so I decided I would have to strip the model back to bare plastic. It took me about two weeks as I was struggling to find a stripping medium, but I eventually found some concentrated Simple Green. The lighter grey base coat was easy to remove, but the paint to which I had added the Ace Lacquer thinner was much more difficult to remove. I also noticed that after stripping the paint off, the areas where there was only the base colour were still fully shiny plastic, but where the 'modified' paint went over the top, the plastic was very very slightly matt. All the surface detail was intact, it just wasn't shiny anymore.

I think that the small amount of Ace Lacquer thinner had allowed the paint to etch into the surface slightly, which accounts for how difficult it was to get off too. I am going to experiment with it, as the matt surface that is left also looks like it is a more paint friendly surface.

Maybe (and you can use the pieces of sprue left over to test) you can try adding some of these more aggressive thinners to see if you can duplicate this; if nothing else it made the paint bloody hard to get off!

I'd be interested to know how you get on

[toadwbg]

I think that the small amount of Ace Lacquer thinner had allowed the paint to etch into the surface slightly, which accounts for how difficult it was to get off too. I am going to experiment with it, as the matt surface that is left also looks like it is a more paint friendly surface.

Yeah, Lacquer will etch the surface, but be carefull as it can be to hot and melt the surface as well if over-applied. Keep it away from clear part!

I'm contemplating using a light acid, like Vinager to etch and clean surfaces. If I get a chance to try this out I'll report back.

[taylorde]

When I try to use tamiya white or gray primer on trumpeter or kitty hawk plastic, the primer seems to bead up, or at least sheen off of some spots. This doesn't happen with other makes like hasagawa, or revel. I've washed the plastic in soapy water, and even washed it with gunzy Sanyo thinner. But to no avail.

What primer do you use with trumpeter or kitty hawk?

What do you use for soap? I use dish detergent, which strips the grease off really well. I scrub it with a used vegetable scrub brush.

DaveT

[ThatJeffGuy]

I've had WEM enamels lift off of my Great-Wall Hobby Fw-189...This was only on an un-primed (Tamiya Fine White) area. I don't usually

wash my kits but my experience and this thread make me suspect the Chinese kit brands need a good wash-up.

There also something called "Plastic-Prep" that should also work. I have some but stopped using it as it seemed superfluous. It's more

expensive than dish-soap though :)

[graves_09]

Based on your description the plastic probably has some oily leftovers from the manufacturing process. Its got nothing to do with the plastic not being "rough" enough. Wash the model using a mild detergent like dish soap. No need to spend money on expensive products like "plastic prep". Also acid or bleach won't do much since you are trying to remove an oil.

Edited March 12, 2013 by graves_09

[Chuck4]

What do you use for soap? I use dish detergent, which strips the grease off really well. I scrub it with a used vegetable scrub brush.

DaveT

I used dish detergent. I tried several weak solvents. None worked. On the KH model the surface of the plastic was matt to start with. So it is not the shinniness of the surface. I think it is the composition of the plastic itself that primer can't adhere to, not any oil, grease or surface texture on the plstic. Simply wipping the plastic with tamiya lacquar thinner or Gunzy sanyo thinner didn't do the trick either.

The only place where the paint did later adhere without any problem is where I first had sprayed a very thick coat of Tamiya lacquar (which beaded and sheened off anyway), left it in place for a few days, and then stripped that coat with Gunzy Sanyo thinner a few days later. I think the trick is to let a temporary lacquar coat slowly etch the surface of the plastic for several days, then strip it off and reprime it. A real pain.

I am curious to know whether the Chinese use a different type of plastic than Hasagawa or Revel.

[Grant in West Oz]

I used dish detergent.

A real pain.

I am curious to know whether the Chinese use a different type of plastic than Hasagawa or Revel.

In my experience, both of those brands has used dud plastic. Revell, unglueable! Hasegawa, unpaintable. ICM used the most stubborn release grease. BP Comprox shifted it.

I've only done 1/72 scale Trumpeter and Hobby boss so far and no problems to report.

G

[Neo]

When i hit greasy plastic i hit it with Rubbing Alcohol drys real fast should take care of it

[stevehnz]

What Neo said, just what I was going to suggest & a lot less hassle than washing in detergent & water. Use cotton buds to clean small parts on the sprues & paper towels or tissues on the bigger areas such as fuselages & wings.

Steve.

[MarcDuhon]

you have to use a true primer... simply using a light acrylic base color isnt sufficient.. there is nothing for that paint to bind to... I prefer lacquer based primers for everything because it actually binds to the plastic... I use floquil thinned with lacquer thinner for all trumpy builds... i also always lightly sand everything if possible with very fine grit...

[MarcDuhon]

I used dish detergent. I tried several weak solvents. None worked. On the KH model the surface of the plastic was matt to start with. So it is not the shinniness of the surface. I think it is the composition of the plastic itself that primer can't adhere to, not any oil, grease or surface texture on the plstic. Simply wipping the plastic with tamiya lacquar thinner or Gunzy sanyo thinner didn't do the trick either.

The only place where the paint did later adhere without any problem is where I first had sprayed a very thick coat of Tamiya lacquar (which beaded and sheened off anyway), left it in place for a few days, and then stripped that coat with Gunzy Sanyo thinner a few days later. I think the trick is to let a temporary lacquar coat slowly etch the surface of the plastic for several days, then strip it off and reprime it. A real pain.

I am curious to know whether the Chinese use a different type of plastic than Hasagawa or Revel.

i used 97% methanol it removes any oils that are there,... just get a no lint cloth and soak with methanol(HEET) and wipe the surface.... you can prob use 97% isopropanol too

[The Loggie]

I can add only a little that is new.

Wash the model parts in warm soapy water (like your Lady used for washing dishes), scrubbing with a toothbrush. 10-minutes pre-soaking doesn't hurt either. Rinse in clean warm water and allow to dry (overnight?).

Try a spray-can of Citadel Miniatures skull white (or chaos black - your call) as a primer. I find that it covers any colour and that it'll even stick to soft Airfix 72-scale soldier figures.

Good luck. George, out............

[loki]

Based on your description the plastic probably has some oily leftovers from the manufacturing process. Its got nothing to do with the plastic not being "rough" enough. Wash the model using a mild detergent like dish soap. No need to spend money on expensive products like "plastic prep". Also acid or bleach won't do much since you are trying to remove an oil.

This!

The oil residue is as a result of the manufacturing process and allows the plastic to be removed from the mould far easier (exaclty the same as resin moulding). The oil based residue should be cleaned off with a mild dishwashing detergent on a damp lint free cloth and then dried with a dry lint free towel or cloth.

Once dry you will have no issues.

I do it all the time as your fingers also leave a similar residue over plastic during the building process, unless you use latex type gloves like some.

Two or three good drops of washing up liquid in a small bowl of luke warm water will work perfectly well and no need for expensive products. Make sure you don't over soap the water or else you'll leave a different residue. Always better to dry the parts off with the lint free cloth or towel rather than leave to dry naturally especially if you live in a hard water area.

Edited March 20, 2013 by loki

[dmthamade]

Don't know how the OP fared, my SOP for prep is light scuffing of surfaces, wash with warm soapy water, Tamiya primer, color coats. On my Trumpeter Harrier i did SOP but JUST the main fuselage didn't take paint. These parts were on their own sprue, all other parts i painted were fine. Hard to believe but paint always pulled off with tape ONLY on the fuselage. I had an experience with a Trumpeter A-7E where i could not glue certain parts together. I've been doing this for a while and have built 7-8 Trumpeter kits with no problems. The fault with the A-7 and Harrier was the plastic. I still have 7 Trumpeter kits in stash, will still happily build them and will still buy their kits, guess i'm just unlucky with some of their stuff.

Don