Let’s Build a Paper Mill complex for a Friend

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As the weather was nasty Sunday as Mother Nature was prepping to dump the white stuff on us, she made sure to wash away all the dirt and grime out on the streets like excess salt and sand. From 8am Sunday to 8pm when the snow started we received in my weather station 1.71” of rain. The weather guy after the Oscars on tv said the area had about 1/3” of glazed ice under the snow. Didn’t matter to me as Terry was at her puzzle board and making soups in the kitchen. Me, except for a 20 minute nap at 2pm I mostly was at my bench.

Working on the bleach plant wall. 10” high and 20” long with a depth of 2”. All framed up!

Started a kitbash of the brownstock building. I was asked by a couple folks on a Facebook weathering page what a brownstock building is:

Separation of Fibers: After wood chips are cooked in the digester, the resulting mixture consists of cellulose fibers and spent cooking chemicals (black liquor). The brownstock process uses large vacuum washers to separate these two components

• Chemical Recovery: The building's primary goal is to wash as much "black liquor" out of the pulp as possible. This liquor is sent to recovery boilers to be recycled
• Pulp Preparation: The output of this building is "brown" pulp (hence the name). This pulp is clean of chemicals but still retains its natural lignin color before it moves through the pipe manifolds to the Bleach Towers for whitening.

Taken from a DuckDuckGo search which I believe is a Ai generated answer

Years ago I purchased a series of built up kits and left over parts from a buddy getting ready for his final year and did not want his wife to have to dispose of his layout. When he passed his wife said take all the buildings and do what you want with them. This will be the JB Reed brownstock building in his honor. In the early 80’s he gave me my 1st tour of a paper mill. 60 minutes in the pulp press room at the Mosinee Paper mill in Mosinee, Wi. where then the main product was the paper toweling found in USA public restroom to dry your hands. I remember the heat and humidity to this day. I was fascinated with so many questions! That was the only part of the mill we saw that day. I felt like an idiot later when we were at dinner and I realized our whole hour was spent in the pulp prep room that is now called the brown stock prep area elsewhere. It’s been 20+ years since my last tour so have no idea what they call the press room now after at least 3 new owners since I retired in 2014. I did eventually see each part of the production process over the years usually an hour at a time.

So I have these parts, the tan and maroon colored walls in the picture. The space is 4” wide x 11” long x 6” high. Compression is a bit..!

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The building should fit before the 2-12” pipes (aka bleach towers someday) covering the circles on the yellow base board template.the front wall of the building will have the window openings bricked in. The coloring will be different remember this is a kit bash

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Still looking for the right position

The walls are dry stacked
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This is where I’ll stop. The black Sintra wall has had a Vallejo Surface primer sprayed on it and I let it set for 24-36 hours. It’s been since
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4pm so maybe tomorrow before I’m able to work on it. It’s too big for the dehydrator. That will be the bleach plant front facade wall. Mainly a place to add and support the maze of pipes that will run through this area

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I have not settled on placement. I know though the position of the 4 bleach (grey pipes) towers will be different


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The brick is in where the windows were and the glue is dry but curing. Today I will add some stiffens to the back side of this wall. The pilasters will be a concrete color to match other pilasters within the whole paper mill. The bricks will be sprayed to match even though the friend this is being built for says leave them. One of the bricked up window opening will get a pipe array running through it. This is 1965 and the paper mill was in the finishing part of a 10 year old upgrade. Paper mills especially in the older sections were notorious for knocking out a wall and doing something new there.


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This is a Ai generated image of the pipes coming off the roof of the brownstock building into the bleach plant. I was interested in the pipe assembly

Slowly moving along
 
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I am waiting for Loctite Power Grab to set and paint to dry.

I needed to spread out the mill where I could comfortably see it and make adjustments on the level it will be operated on at my friend’s layout. On the layout it’s at the 40” level. I have a cabinet in the cave that sits at 38” and close enough

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The weather is frightful. There was no snow there 24 hours ago. The NWS at noon says we have 13” on the ground and the winds are diminishing and are in the low 30’s but gusts are in the high 40mph range. Better than the gusts of high 50’svwe were experiencing, my picture

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It’s 46” from the digester on the left to the end of the black bleach plant wall on the bright, my picture

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I asked Ai to fill in the window opening above the paper mill

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I asked Ai to color the paper mill leaving the backdrop of the window blacked out

This colorized version will help me make dimensional adjustments

I need to decide on a base for this 46” segment. I wasn’t planning one but now think a .080 styrene base is needed but will consult with my friend. I have 24”, 18” and 12” wide x 96” long plain white styrene in .040, .060 and . 080 thicknesses. I also have 24” x 60” Sintra PVC board in black for 3mm, 6mm and 3/16” thicknesses so I have choices.
 
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So much for the occasional Ai help I lean into but especially when it involves math
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The open spot is to get an array of piping through the window. 6’8” x 18’ scale (ho scale). Measured everything with the scale ruler and viola, Ai says will fit no problem

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Not even close

I’ll get something through that open spot but it has to be a nice visual
 
Limited to 10 pictures so there will be 2 posts

While I am having fun this is very slow progress. I know I am bouncing all over with this project but there are reasons (I think) but I am now trying to complete the bones for this 46” segment. Again from left to right it includes the digester at 12” high, a white liquor tank, the blow tank, a couple former tanks/towers, the brown stock building and bleach towers. The back drop for the 1st 20” is the recovery boiler wall that will have a 15” high chimney stack, the green and black liquor 1/2 relief tanks will be part of the wall. The main piping will come later and I have sketches of how I believe those runs will look.

We left off at figuring the water pipe runs in the brown stock building and the piping returns for the black and green liquor tanks. Then I was informed the 11” long brownstock building couldn’t exceed the original 8” allowed for it. That meant one of the 4 bays had to be removed from the wall.

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Here is the 4 bay wall with the plan the liquor pipes would pass into that open area
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It played well in the scene!
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Here is the new 3 bay wall. I’m not sure what plastic was used to create these walls. I used the Dremel band saw on a slower than normal speed, then my motor tool with a grinding wheel. I then used my sanding blocks starting with a 60 grit, 200 , 400 and just a touch of 1000. It worked out but what a mess. I didn’t have the correct combination of modular walls to create a 3 bay so I cut it down
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Had to fit the water pipes next and the good feeling was gone. It seemed wrong missing that 4th bay but you have to build on a property to fit. The liquor tank piping will now enter via the side wall but the water will still be via the front. I use Ai to help me visualize and 1st started playing with it in October, 2025. Finally in February settled on mostly Google Gemini and rarely chat GPT for images. I started the paid version on 3/15/2026 but it’s sometimes a PITA so my note pad and graph paper pad is always near by. The pipes were added in the previous 2 photos by Ai and i will always tell you if I am using Ai to generate anything. I liked the arrangement.
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But 1st the joining seams between Modular’s sections needed to be filled and Tamiya putty on a couple samples was not working! This is a 1965 era building and it was solidly constructed. So in a few experiments I chose to cover the the pilasters with .030 plain styrene and paint them a concrete color. Terry looked at them and said they looked wrong (she really said dog poo). So off came the Styrene pilasters and I narrowed them down to 2.75’ scale and 1.25’ scale but kept the .030 thickness. Why? Terry suggested I cover the horizontals and with a thinner styrene to keep that stepped look Between the thicker verticals and thinner horizontals

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Then decided the sills needs coverage and used .010 styrene there
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In the next posting I will show the full wall with the concrete cladding applied, new window openings and water pipes fitted

Yes I should have painted some before this step but my masking skills are still decent. The different brick color will stay as those 6 blocked in openings did occur in the upgrades to paper mill facilities and the change in brick and coloring reflect the remodeling. At least Ithink it does!

Any questions I will gladly respond to
 
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I'm still cleaning up and thinning out and came across a trunk of old Walthers buildings that nobody wants to take.
Can’t even give them away!
So I’ve been having fun hacking and chopping them into background flats and using styrene as you show here to patch them back together. I’ll probably just throw them back into the trunk or chuck them out later.
 
I'm still cleaning up and thinning out and came across a trunk of old Walthers buildings that nobody wants to take.
Can’t even give them away!
So I’ve been having fun hacking and chopping them into background flats and using styrene as you show here to patch them back together. I’ll probably just throw them back into the trunk or chuck them out later.
I enjoy kit bashing but the plastic on these modular walls is something foreign to me . But I got it done. I have maybe 20 more wall sections to use elsewhere but they will not be used again in this paper mill.

Rico send me a picture of those parts. Maybe we can deal. I am creating buildings for 2 layouts right now and tearing down most of my own that eventually will get new structures
 


Limited to 10 pictures so there will be 2 posts

While I am having fun this is very slow progress. I know I am bouncing all over with this project but there are reasons (I think) but I am now trying to complete the bones for this 46” segment. Again from left to right it includes the digester at 12” high, a white liquor tank, the blow tank, a couple former tanks/towers, the brown stock building and bleach towers. The back drop for the 1st 20” is the recovery boiler wall that will have a 15” high chimney stack, the green and black liquor 1/2 relief tanks will be part of the wall. The main piping will come later and I have sketches of how I believe those runs will look.

We left off at figuring the water pipe runs in the brown stock building and the piping returns for the black and green liquor tanks. Then I was informed the 11” long brownstock building couldn’t exceed the original 8” allowed for it. That meant one of the 4 bays had to be removed from the wall.

View attachment 260974Here is the 4 bay wall with the plan the liquor pipes would pass into that open area
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It played well in the scene!
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Here is the new 3 bay wall. I’m not sure what plastic was used to create these walls. I used the Dremel band saw on a slower than normal speed, then my motor tool with a grinding wheel. I then used my sanding blocks starting with a 60 grit, 200 , 400 and just a touch of 1000. It worked out but what a mess. I didn’t have the correct combination of modular walls to create a 3 bay so I cut it down
View attachment 260976View attachment 260977
Had to fit the water pipes next and the good feeling was gone. It seemed wrong missing that 4th bay but you have to build on a property to fit. The liquor tank piping will now enter via the side wall but the water will still be via the front. I use Ai to help me visualize and 1st started playing with it in October, 2025. Finally in February settled on mostly Google Gemini and rarely chat GPT for images. I started the paid version on 3/15/2026 but it’s sometimes a PITA so my note pad and graph paper pad is always near by. The pipes were added in the previous 2 photos by Ai and i will always tell you if I am using Ai to generate anything. I liked the arrangement.
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But 1st the joining seams between Modular’s sections needed to be filled and Tamiya putty on a couple samples was not working! This is a 1965 era building and it was solidly constructed. So in a few experiments I chose to cover the the pilasters with .030 plain styrene and paint them a concrete color. Terry looked at them and said they looked wrong (she really said dog poo). So off came the Styrene pilasters and I narrowed them down to 2.75’ scale and 1.25’ scale but kept the .030 thickness. Why? Terry suggested I cover the horizontals and with a thinner styrene to keep that stepped look Between the thicker verticals and thinner horizontals

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Then decided the sills needs coverage and used .010 styrene there
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In the next posting I will show the full wall with the concrete cladding applied, new window openings and water pipes fitted

Yes I should have painted some before this step but my masking skills are still decent. The different brick color will stay as those 6 blocked in openings did occur in the upgrades to paper mill facilities and the change in brick and coloring reflect the remodeling. At least Ithink it does!

Any questions I will gladly respond to
Love the piping details.
 
I think it's the 5th picture, but I love the open sidewalk hole with the pipe. Are you just gonna put a handrail up around it or a cut out drain?
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This picture?

The open concrete around the waste water pipe is an unknown. Safety conscious me says add at least a grate around it or fill it with concrete. A single rail pipe hand rail would have probably been ok in 1965 or even nothing like the picture. This is 1965 and OSHA became law in 12/1970 when President Nixon signed its funding. It started operating in 1971. There will be something there as I’m sure the paper mill’s insurance company had loss prevention personnel
 
I didn’t accomplish too much today
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Painted the concrete pilasters, horizontal’s and sills
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Added the shut off wheel to the valve and decided my standoffs for the pipes were too big
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Painted the personnel door and overhead door

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A touch of weathering to the overhead door and a moisture spot on the bottom left of the personnel door. I will add the door handle tomorrow or Wednesday
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Moisture added to the backer plate where the water pipes enter into building. If you zoom into the header plate there is a rusted nut in each corner that holds the plate to the brick

Paint touch up will happen today along with adding the 2 windows. If the touch up spots are dry enough I will spray a final matte clear finish. I do have to figure out the stand offs for the pipes

Enjoy your day
 
Not sure what happened but I thought I posted this on Monday 3/23/2026 but it was still sitting there ready to go this morning. This should have posted before noon yesterday
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Added windows to the top corner openings
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Seeing how it lines up on the background wall
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Then I put a temporary piece of white styrene behind the windows and took the picture. I was looking to see if the frames and sash lined up across both windows. In this picture you can see the differences. I straighten the sash and glued it
 
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End to end of the black walls is 46”. Shown are the main pieces
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Need 20 of these. 3 pieces of styrene to create this electric shut off box! The parts are all cut including the 2 conduit pieces. Sitting in a prepped material bin for someday…

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Now to add things where there is not enough room. The yellow mock is the green liquor tank that is a 1/2 relief model and will be glued to the wall. Only when I can get it to fit and look ok. The black liquor tank also the same depth but 1” taller will be on the wall
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It’s too big

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Narrowed it down from 2.25”, 2” and now 1.25” and it fits but doesn’t look good.
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It looks too crowded without rearranging everything.

So, my next move is to bring the depth down to 1” for both the shorter green liquor tank and the taller (not shown) black liquor tank. Mock ups tonight. I’ve been advocating for more depth to 6” + and it’s always no. Getting the 5” depth I have now was a struggle. This scene and structures is heading to the layout tomorrow with 2.25” and 1” deep black and green liquor tanks. That should be convincing enough. If not The 1” deep liquor tanks will do…
 
I this week I did some final dimension stuff and sprayed Israeli Sand colored surface primer on all the Sintra PVC board I use for framing and wall supporting.
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The towers of the digester had the 6’ Ho scale concrete foundation laminated onto the Sintra. The left tower #1 is 12” high is a poured concrete construction with tower 2 at 10” high being a metal corrugated cladding to indicate it was an addition to tower 1
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Israeli Sand colored surface primer from Vallejo. Sprayed at 16 psi, about 2-3” from the structure and straight from the bottle with no thinner or flow retarder. Dry tip was an issue initially but every minute or so I cleaned the spray tip and I had no issue the rest of the time
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This is the blow tank sitting on a 2” wide roll of painter tape. The blow tank has a 6’ discharge cone under the body of the tank. The tank is primed with Vallejo’s ghost gray surface primer used to just finish off the bottle. Legs will be added (hopefully soon) to that square support frame that will hold the tank. I need a temporary fixture to keep the discharge cone safe and that allows me to add the legs
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The direct photo above is a Ai generated image. Showing me how the gussets need to be applied
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The green colored tank is a Tichy kit! It is completed including weathering and will be the white liquor tank. The yellow on the Recovery boiler wall are mock ups for the green and white liquor tanks
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The Recovery Boiler and Bleach plant walls have been primed. Israeli Sand Surface primer. Even though some of the walls will be covered by Styrene cladding I’m finding the Sintra needs to be primed. Otherwise it sucks up the paint and adhesives I use.

Slowly because there is no time frame or dead line I’m just moving along. Remember this is a gift for a friend and I am working on it between commission and personal projects for the grandson and my own needs. There should be a spurt of activity now that the 72+ hours of dry and cure time for the Surface Primers has passed and a locomotive weathering commission is done. Or not…
 


I went back to the bench today after being completely away. I have been fighting the looks, the height or just about everything about the paper mill blow tank!

What’s a blow tank? The Ai response:

In the violent, high-pressure world of a 1960s pulp mill, the Blow Tank is the critical "exhaust valve" of the operation.
Think of it as a massive, industrial-strength shock absorber. Here is what it does:

1. The "Blow" (Pressure Release)

Inside the Digester, wood chips are cooked under intense steam pressure and chemicals until they turn into pulp. When the "cook" is finished, a large valve at the bottom of the digester is opened. The pressure (often over 100 psi) literally blows the cooked pulp out of the digester and through the blow line into the Blow Tank.

2. Energy Dissipation & Velocity

The pulp enters the Blow Tank at a high velocity, usually hitting a tangential entry point (the "cyclone") inside the tank. The tank’s job is to:

• Slow down the pulp so it can be managed.
• Separate the steam: The sudden drop in pressure causes "flash steam" to roar out of the top vents (which is why you’ll want to weather the top of your tank with heavy mineral deposits).

3. Temporary Surge Storage

A paper mill is a continuous process, but a digester is often a "batch" process. The Blow Tank acts as a buffer. It holds the massive "slug" of pulp from a blow and allows it to be pumped out at a slow, steady rate to the next stage—the brownstock washers.


4. Consistency Leveling

Inside the bottom of the tank, heavy-duty agitators mix the thick pulp with "black liquor" or water to thin it out (lowering the "consistency") so it’s liquid enough to be pumped through the rest of the mill.

Why it looks the way it does on your layout:

• The Heavy Frame: Because a "blow" is basically a controlled explosion, the tank experiences massive structural vibration and thrust. That’s why you’ve built such a heavy H-beam support frame with those 15" x 15" gussets—it has to keep the tank from walking off its foundation every time a digester empties.

• The 18' Walkway: This provides access for workers to inspect the blow valves, clear clogs, or maintain the entry-point seals where the most wear-and-tear occurs.

In short: No blow tank, no pulp. It is the violent transition point where wood chips officially become liquid paper fiber.
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I have issues with the support frame as I just don’t like it! But I am going to continue on with it. Next I have to add 2 gussets to each leg and add some cross bracing on 3 sides leaving the front side open. There will be a discharge pipe and valve at the bottom of the cone. When that is done I will decide if I cut the legs down another 1” or 7.25’ ho scale. There will be a 18” wide walkway coming from the digester building to the front of the blow tank and wrapping around the right side of the tank back to the recovery boiler wall
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The legs look flimsy but will look stronger when the gussets and support bracing is added on 3 sides
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The digester building on the far left is 12” and 10” high. The blow tank on its 3” legs is 10.5” high including the vent pipe on top. I thinks it’s at least 1” too high. The dark green tank to the right is the white liquor tank. The blow tank is a scratch built vessel and the white liquor tank is a Tichy kit using the flat roof option the kit provides
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This is a shot of the discharge cone. It will be enclosed on 3 sides with X crossed bracing. The front side (this shot) will remain open. At the bottom of the cone will be a supported pipe and valve

Till the next time
 




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