Painting hydrocal building

[PED]

Starting to assemble the first hydrocal building (N scale) I have ever done. After some research on painting hydrocal, I can see that a primer is needed to help seal the surface so I will do that. Normally I airbrush the topcoat paint on but most of the "how to" sites I hit indicated they typically brushed on the top coat with a watered down acrylic. I should note that the sites I went to typically did a lot of weathering and fine detail work so a brush on approach might work best for that. They were also much larger scale structures than the very small structure I am doing in N scale. Although I do expect to do some minor weathering, this is not a showpiece structure so weathering is not overly important. Also, the details on this kit are very faint and I am afraid that brushing on a paint will obscure all the detail.

Is there any reason I should avoid an airbrush and do the brush on approach?

[Little Timmy]

I have only done a few ( maybe 3 ) Hydrocal building's that I cast myself.

( I used Design Preservation walls as the master's for my mould's... please dont tell them I turned One building into a few..... They will cry " Intellectual Property" and hunt me down. ) 

I discovered that if you just paint raw Hydrocal( brush or spray ) the Hydrocal will "Suck up" a LOT of paint. So I started to "Prime" them first with Testor's Gloss-cote. After that, Spraying on paint was easy.

As for the "Brush painting", I can only venture a guess that it would be to give the Hydrocal some "Tooth". ( So later layer's of paint would stick,) I do use a brush for the small detail's though.

HOWEVER: I'm no expert on this subject. I'm "self taught" and could be full of escaping Steam....

 

[HO-Velo]

As per Downtown Deco Inst. priming hydrocal structures with a few light coats of white spray paint is a good prep.  After drying overnight brushing on the primary color 25% acrylic craft paint to 75% H2O works good, more coats can be added to ones liking.  Weathering washes of 1 part paint to 9 parts H2O can be brush applied later.   Careful use of a hair dryer or heat gun on low between coats can speed things up.

Airbrush applied paint is good too, but after the prime coats. 

For example the tile work on Sportmans Liquor is airbrushed enamel, brick work brushed acrylic craft paint washes, concrete trim brushed full strength acrylic craft paint.   

Regards,  Peter 

 

 

[Phoebe Vet]

I don't prime.  The hydrocal soaks up the diluted paint, but I like the look of that.

[SeeYou190]

I use a lot of hydrocal castings for abutments, piers, and wall. I also have built several hydrocal buildings.

.

I prime them with several thin coats of Apple Barrel craft paint. I used the dark gray "Pewter" color. I thin this about 70/30 water/paint. The casting does suck it up, but that it the idea. Suck up the primer and save the paint. Usually 3-4 coats of primer is good. No details are ever lost under thinned paint.

.

I always brush paint my hydrocal, and most other buildings.

.

Peter is the undisputed master. Maybe you should just listen to him.

.

-Kevin

.

[hminky]

Know this isn't a building but have a "what-i-did" building a timber portal.

http://www.pacificcoastairlinerr.com/4x8/portal/

Hated the way the the plaster took the color. The color is effected by the plaster. So I primed the surface with Kilz2 latex primer. Then the primer is being stained or painted. There is no way the plaster would ever look like weathered woood.

Thank you if you visit

Harold

 

[RR_Mel]

For Hydrocal & Plaster of Paris I use Woodland Scenics stains.  I prefer stain over painting.  I don’t use any primer and I learned the hard way to not seal them after staining.  I had Fluorescent lighting (cut over to LEDs this summer) and it severely fades colors.  Anything sealed will not accept a fresh coat of stain.   

 

 

Mel

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[HO-Velo]

It should be emphasized that the 3 or 4 coats of white spray can primer paint are applied very light and allowed to dry to the touch between coats, such a priming still allows for some absorbtion of the subseqent craft paint washes into the castings in a moderately uneven manner.

At the same time airbrushing enamel over the tiled areas did require a few coats for  solid coverage.   

Oh and btw, a humble thanks to Kevin, but I'm a jack of many modeling techniques, master of none.

Thanks & Regards, Peter  

[MisterBeasley]

I haven't done any Hydrocal buildings but I've done lots of rock face castings and rock walls.  I like ink washes which Hydrocal takes very well.