Assembling "sealed" wood parts

[tstage]

dknelson

Ah yes, I see the problem. Do you get much benefit from sanding sealer-ing (to coin a phrase) such tiny parts, since the usual goal is to sand down the sanding sealered wood to get a smooth metal like finish? One though would be to mask the edges that are to be glued before applying sanding sealer. Not sure tape would work but perhaps a very careful application of those masking fluids that can be pealed off after painting (or sealing).

Without seeing the project right in front of me I do not know if it is useful to suggest deferring the sanding sealer application until AFTER at least some of the more persnickety glueing. Those parts could interfere with the surface sanding that follows sanding sealer

Dave Nelson

Hi Dave,

The project is a Quality Craft Models '51 PRR H-32 covered hopper:

If I knew exactly where each of the parts was to be placed then - yes, I would agree - masking the shell before or sealing the parts after assembly would be advantageous.  Unfortunately, there are too many corners created with the angle brackets to make sanding feasible.

Tom

[dknelson]

tstage

 

 

dknelson

My experience with sanding sealer suggests that it does not soak in all that deeply so I'd focus on the areas that will be mating with other pieces and lightly sand right there.

 

 

Thanks, Dave.  That should work for the larger pieces but will be more challenging for the thin & delicate strips - e.g. 3/64" angle brackets.  Those I'll use CA to apply them to the surface of the covered hopper.

Tom

 

Ah yes, I see the problem.  Do you get much benefit from sanding sealer-ing (to coin a phrase) such tiny parts, since the usual goal is to sand down the sanding sealered wood to get a smooth metal like finish?  One though would be to mask the edges that are to be glued before applying sanding sealer.  Not sure tape would work but perhaps a very careful application of those masking fluids that can be pealed off after painting (or sealing).  

Without seeing the project right in front of me I do not know if it is useful to suggest deferring the sanding sealer application until AFTER at least some of the more persnickety glueing.  Those parts could interfere with the surface sanding that follows sanding sealer

Dave Nelson

[tstage]

hon30critter

Hi Tom

I apologise. I had structures stuck in my mind when I was typing up my post. Obviously much of what I said isn't relative to your project.

Cheers!!

Dave

No problem, Dave.  Some applicable info nonetheless so thank you.

Tom

[tstage]

Thanks, Mark.  I did purchase some Plastruct 3/64" angle iron and will use that instead of the wood angle iron that came with the kit because the styrene will provide cleaner/sharper lines.  I may do the same for some of the other smallish wood strips once I deciper the assembly instructions.

Love the QCM kits.  The assembly instructions, however, leave much to be desired conveying how some of the parts are oriented on the model.  I'm having to look at prototype photos to accomplish that and those are sometimes not very plentiful; making it even more of a challenge.

Tom

[hon30critter]

Hi Tom

I apologise. I had structures stuck in my mind when I was typing up my post. Obviously much of what I said isn't relative to your project.

Cheers!!

Dave

[mvlandsw]

Tom,

   Unless you want to build the kit strictly as designed, I would use plastic strips and angles instead of trying to seal the wooden ones. They could be attached with CA glue.

  I believe that the H-32 cars were painted a gray color. There were some that got PC green or CR red.

Mark

[tstage]

hon30critter

Hi Tom,

Before you assemble the kits I would suggest painting any bits that will be different colours first. That will give you very sharp delineation between the colours and you don't have to worry about paint buildup in areas like inside corners or between window/door frames and walls.

Thanks for the tips, Dave.  The craftsman kit is a QCM PRR 51' H-32 covered hopper and will be all one color.  (IIRC, the prototype was white.)  I'll be using Tamiya lacquer paint, which sprays on very thin so I'm not too worried about over-covering details or paint build-up.

I use CA to glue the painted surfaces together. I try to apply it to the non-visible sides of the joints in order to minimize the amount of glue that wicks through to the visible sides.

I also agree with sealing the wood. Sealing the wood first will reduce the number of coats of paint required to properly cover areas where the wood tends to be very absorbent, like the edges of laser cut pieces. I don't use a dedicated wood sealer. All I use is cheap automotive primer. Be sure to paint both sides with fairly equal amounts of paint.

I used only primer on my QCM 61' well-hole flatcar.  The wood grain showed through somewhat noticeably - even after several coats of paint - so I decided to try sealing the wood this time. 

One other fairly critical step to prevent warped walls is to glue reinforcing strips to the insides of any flat panels, preferably before doing any painting. If you have painted or sealed the walls, just use CA.

Cheers!!

Dave

The interior is supported/reinforced by three fairly thick square blocks, as well as the angled ends and beveled top.  The shell is completely enclosed, sealed with two coats of sanding seal, and sanded smooth.  The chances of it warping are pretty much nil - even if I submerged the entire shell into water for a lengthy amount of time.

Tom

[hon30critter]

Hi Tom,

Before you assemble the kits I would suggest painting any bits that will be different colours first. That will give you very sharp delineation between the colours and you don't have to worry about paint buildup in areas like inside corners or between window/door frames and walls.

I use CA to glue the painted surfaces together. I try to apply it to the non-visible sides of the joints in order to minimize the amount of glue that wicks through to the visible sides.

I also agree with sealing the wood. Sealing the wood first will reduce the number of coats of paint required to properly cover areas where the wood tends to be very absorbent, like the edges of laser cut pieces. I don't use a dedicated wood sealer. All I use is cheap automotive primer. Be sure to paint both sides with fairly equal amounts of paint.

One other fairly critical step to prevent warped walls is to glue reinforcing strips to the insides of any flat panels, preferably before doing any painting. If you have painted or sealed the walls, just use CA.

Cheers!!

Dave

[kasskaboose]

I'd suggest wood glue also. Since the opening is large, I would suggest putting some on scrap paper and apply with a toothpick. 

[tstage]

dknelson

My experience with sanding sealer suggests that it does not soak in all that deeply so I'd focus on the areas that will be mating with other pieces and lightly sand right there.

Thanks, Dave.  That should work for the larger pieces but will be more challenging for the thin & delicate strips - e.g. 3/64" angle brackets.  Those I'll use CA to apply them to the surface of the covered hopper.

Tom

[zstripe]

dknelson

My experience with sanding sealer suggests that it does not soak in all that deeply so I'd focus on the areas that will be mating with other pieces and lightly sand right there.  I'd like to think that would expose enough unsealed wood that standard wood glues would work.  

Dave Nelson

 

I agree with Dave Nelson's post, more than any others. Straight forward advice and I have built many wood kits over the yrs. starting the Hobby in 1950. Including tin, (Sudam kits) learned how to solder on those...........and they did not have no 1/16th tip back then, just an iron resembling a space gun, from the Flash Gordon days! Hahahah....

Take Care! 

Frank

[dknelson]

My experience with sanding sealer suggests that it does not soak in all that deeply so I'd focus on the areas that will be mating with other pieces and lightly sand right there.  I'd like to think that would expose enough unsealed wood that standard wood glues would work.  

Dave Nelson

[BradenD]

Tom, aliphatic resin glue is very strong and bonds wood to wood very well. However, seals would definitely weaken the joint as glues need to be able to penetrate into the wood fibers. I would test it to see if it gives the hold you like. It isn't too expensive and it's much cheaper to waste glue than kits.

[tstage]

Darth - Are you saying Sig-Bond aliphatic resin glue should work on sealed wood?

Tom

[Darth Santa Fe]

I use Sig-Bond aliphatic resin glue for all of my wood kits.  It dries fast, holds strong, cleans up easily enough and closely matches the color of wood.

If wood glue doesn't work, liquid super glue should do the job!

[richhotrain]

Tom, I have assembled wood kits with wood glue, but I have not attempted to use wood glue on sealed wood. Wood glue works best by soaking into the wood pores. I just wonder if a construction adhesive wouldn't be a better choice. In any event, it would be best to experiment with some scraps if you can.

Rich

[allegedlynerdy]

I'd always recommend using woodglue when putting together wood models. Gives a good bond, a good amount of working time, and you don't have to worry about it messing with future paint application like CA glue can. Personally I prefer staining the wood before assembly, and then doing another stain coat after painting. I'd recommend making sure to paint with a paint that has a lower moisture content to prevent warping. 

[tstage]

I will be assembling a few wood craftsman kits that have their individual wood pieces sealed with sanding sealer.  Once assembled, the kits will be painted and decaled.

A couple of questions...

1. What adhesive would you recommend for gluing the parts together?
2. Is there any additional surface prep needed before painting the assembled model?

Thanks for the help...

Tom