Jump to content

Micro holes in resin


skyskooter

Recommended Posts

I am building a Planet Models Martin Baker MB 5. It is a resin kit to 1/72 scale. I have just reached the finishing stage and sprayed the model with Halfords Grey Primer. A nice finish resulted. I then airbrushed a coat of Vallejo White Primer and to my horror there are micro holes all over the upper surfaces of the wings. How do I get rid of them? I know there are micro fillers but are they going to fill the panel lines as well as the micro holes? Can you help please.

Link to comment
Share on other sites

I use micro filler (airbrush ready)

with a cocktail stick, if I’m targeting one area. Yes it will fill panel lines but it scrapes out easy enough. Again use the good end of said cocktail stick before it dries properly!

 

(based on cellulose base paint)

if it’s just a few holes I’d not even bother to dirt the airbrush.

Link to comment
Share on other sites

hi @skyskooter just to be clear are the holes present on the model kit (they've been there the whole time but you didn't see them until the white primer exposed it), or are the holes microbubbles created from the vallejo white primer? 

 

if the former, filling it as @It's a disease is the way to go. If it's the latter, I would recommend stripping the model (or careful sanding of the surface if stripping is not an option) and re-priming with something different. Though any reason you are using two primers?

Link to comment
Share on other sites

Thank you for your advice.

 

Your first assumption is correct. The micro holes were there on the top surfaces of the wings all along. I never saw them until the white primer was applied. I can even insert the tip of a fine pin into most of them. They were not apparent after the initial coat of Halfords Grey Primer. That is an Auto acrylic primer which has excellent adhesion to the substrate. I use it because I am not convinced that Vallejo acrylics always etch well on resin.

 

I will do as it’s a disease says. In fact I have on order AK Interactive White Primer and Microfiller but it has not yet been delivered.

 

 

Link to comment
Share on other sites

yeah that's a bummer, but one of the benefits of primer - seeing all these things missed on initial inspection. 

 

Two more things: depending on how big these small holes are, you may be better off with putty or something like Mr. Surfacer 500 to fill the holes - if the AK isn't viscous enough. 

 

And secondly in the future I can recommend Stynelrez primer (rebranded as Ultimate Primer from Ultimate Modelling products and One Shot by Mig Ammo if those are more accessible for you) to be used on resin. The "rez" part of the name is supposed to symbolize it works on resin. Just a warning though that the white is a bit more difficult to apply and not as smooth as the grey and black, and you may have to push up the psi. 

 

good luck!

Link to comment
Share on other sites

May I come in here with a similar problem please.  I do a lot of resin builds and one kit is really causing me problems with micro holes.  Normally I just fill then wet 'n dry to smooth, but this kits causes a reaction when applying these primers and the affected area just bubbles and won't seal.  Anyone else suffered this and have a solution?

 

cheers,
Mike

Link to comment
Share on other sites

@bootneck

 

could it be release agent?

————————————-

Long shot but

Try targeted? washing with a brush dipped in thinner or ipa prior to paint.

Though you most likely have!

Failing that cyano but it’s a pain to treat/sand.

 

i usually find cyano harder than the surrounding area but I’ve read about timing it just right.....so it hasn’t fully hardened.

i never get it right.

 

—————-

Im not sure what ak solvent is?

but, the brand I use is cellulose base.

Zero/hiro (rapid evaporation)

 

in any case, leave a drop or two on your pallette for a few (undisclosed time frame!) basically keep an eye on it until it congeals a bit.....

(it will thicken up as the solvent evaporates, time depends on humidity/temp)

 

then you’ve a more pasty product.

 

its messy but efficient.

i keep a near empty jar that has had the lid off for a while for just this purpose!

 

 

Hope that lends itself to a happy new year!

Link to comment
Share on other sites

I have encountered this problem many times, mostly on older resin kits.  Most manufacturers have improved, and many now use pressure casting, which is the holy grail of resin casting, for eliminating defects in resin casts.

 

That being said, the thing that works best for me is to first, closely inspect the bare resin surface with a good light (not necessarily diffused) held at a low angle across the parts being inspected.  This will usually disclose the little buggers, after which, I fill the with a coat of 3M Glazing and Spot Putty.  This was developed to finish pinholes in Bondo during car repairs, and because it will feather edge out to nothing, it fills tiny (or larger) pinholes very nicely, and sands even perfectly.  Since this is a product designed to work with auto filler, look for a similar product in your country at auto body shops, etc., although here in the USA, it is also available in the big box stores, in addition to auto parts stores...

 

Ed

Link to comment
Share on other sites

Oh, one thing I forgot to mention -- do the filling one panel at a time, masking off the panel with tape, and you should pretty much be able to save most of the panel lines easily.  Just sand down to the thickness of the tape, then use a sanding twig, etc., to sand down the rest, as long as it's a very fine grit sanding twig.  You can just snip off the end of the twig as you go, when it clogs up with putty.  I also use a fine wire brush to clean the sanding twig, between cutting them off.  The small twigs will give you very good ability just to sand very small areas.

 

Ed

Link to comment
Share on other sites

Having built many.many resin kits, mainly 1/24 KFS and 1/35 Accurate Armour, manufacturers are aware of these "faults" and tend to warn you about these difficulties in the instructions.  They offer a solution, superglue and a needle, just apply the glue to the hole and after its dried, sand it down...............problem solved, for the really BIG holes I add Baking powder to the superglue(after applying it the model, its just like a puddle, drop the powder into the puddle, you can use Talculm powder which has finer granules, Bicarb of soda also can be added to the glue, depends on your preference.  

 

I used superglue and baking powder a lot when building the Airfix Vulcan, came in handy when overscribing and moving panel lines on the wings and body.

 

I tend to use this filler now in preference to other well known "putties" as this mix is just as good, it is an instantantious filler, goes off within micro seconds of apply powder and soda and does not shrink.

 

Happy New Year

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...