Depressed center flat car

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makinsmoke
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Re: Depressed center flat car

Post by makinsmoke » Sun Dec 19, 2021 7:54 am

Ah. Reread your post.

If you are using actual decals then a top sealer is needed. If paint masks or vinyl stick ons then no.

Terr1bleone
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Re: Depressed center flat car

Post by Terr1bleone » Sun Dec 19, 2021 10:54 am

I am using vinyl, but the satin clear spray on enamel was to soften the color of the car not seal the decals or add additional protection.
-mike

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makinsmoke
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Re: Depressed center flat car

Post by makinsmoke » Sun Dec 19, 2021 5:16 pm

Ah.

Just paint the car with satin enamel or your choice of paint. I’ve had plenty of luck with rattle cans. With your limited large flat areas cans should be just fine. Also, lighter coats will help prevent runs.

I’d do anything to keep from putting a clear coat on.

Again, just my two cents Mike.

Terr1bleone
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Re: Depressed center flat car

Post by Terr1bleone » Thu Jan 06, 2022 11:05 pm

I have been busy with the holidays and work, but managed to get a good start on the boards the past few nights.
Cutting them to size was a little more labor intensive then planned. They were first rough sized on a table saw for me out of a 16”x 12’ 3/8 thick piece of white oak, which landed them close but on average .012 thousands too large and not very square overall. This wouldn’t be a huge deal, but since the holes are already in the deck plate, it adds up to about 3/8” error in the holes from the first to last board.
the fix is onto the milling machine since I don’t have many woodworking tools.
A 3/16” slot was milled into some soft jaws. I was originally going to make the jaws the same length as the boards, but opted for an easier setup since it was a one time deal.
Two small drill press vices were used as support for the end, a 2 flute 3/8” solid carbide center cutting end mill was used.
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Then to square up one end on the belt sander
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Finally to the chop saw station to size.
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The first board also required a slot to fit the deck so that was also added.
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Now the boards are sized they still need to be drilled, sanded and stained.
-Mike
Last edited by Terr1bleone on Fri Jan 07, 2022 12:10 am, edited 8 times in total.

Terr1bleone
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Re: Depressed center flat car

Post by Terr1bleone » Thu Jan 06, 2022 11:06 pm

A quick go-no-go gauge was made to verify the length.
33599F07-AC00-4ECD-AEEE-8AF6D2C7E296.jpeg
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Preview of the deck boards layed out.
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The boards (that could have) been provided by John @ pacific design shops for an small extra fee would have been a much better option. I had thought they would come straight off the table saw ready.
-Mike

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rmac
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Re: Depressed center flat car

Post by rmac » Fri Jan 07, 2022 1:05 am

A table saw should have produced square ends on those boards, but I wouldn't consider the .012" error in width to be out of line at all. If those boards are about an inch wide (as they appear), you can expect them to expand and contract by as much as forty or fifty thousandths just with normal changes in ambient humidity.

Let's assume you install them on your frame with no gaps between the boards. If you do this when the humidity is high, then they will shrink when the humidity drops and gaps will develop between the boards. That probably won't hurt anything. But if you install them with no gaps in a low humidity environment, then they will expand when the humidity goes up and most likely buckle in some unsightly fashion.

Click here for a calculator that predicts the dimensional changes in various kinds of wood as its moisture content changes. And here begins a series of posts by another gentleman on this board who learned all this stuff the hard way.

The bottom line is that when working with wood, you have to accept that it IS going to move, and design accordingly.

-- Russell Mac
Last edited by rmac on Fri Jan 07, 2022 12:42 pm, edited 2 times in total.

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ccvstmr
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Re: Depressed center flat car

Post by ccvstmr » Fri Jan 07, 2022 9:39 am

Mike...

Will 2nd RMAC's comments about your wood deck. Whether due to temperature/humidity changes AND/OR if you're going to stain your deck boards (which adds moisture to the wood), dimensional changes ARE going to take place. Wouldn't worry so much about length or thickness of your deck planks...but width could be an issue. Best to leave a small gap between your deck boards for just that purpose.

Here's a photo from a Prec. Steel Car deck I built back in 2004...
130-3052_IMG.JPG
Looking in the real world, flat car decks and box car floors were anything but pristine. Nicely laid floors like tongue and groove work are best left for a home hardwood floor. RR floors take a beating over the life of the car as loads need to be cribbed and anchored for shipment.

As noted by RMAC...I cut/fit some scribed basswood tight into a machined recess in some aluminum doors. Looked good when I was done. The aluminum doors might have expanded...but not as much as the basswood. Even when the basswood was painted on all sides. Had to go back, cut/sand the basswood inserts slightly undersized, apply a backing board for additional support to prevent buckling and then use a different kind of contact cement with greater contact area to secure.

This issue is not something that would come to mind during the time of construction. But, if you take the time now, you can save yourself some time (and aggravation) on down the line. Carl B.
Life is like a sewer...what you get out of it depends on what you put into it!
I don't walk on water...I just learned where some of the stepping stones are!
I love mankind...it's some of the people I can't stand!

Howard Gorin
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Re: Depressed center flat car

Post by Howard Gorin » Fri Jan 07, 2022 2:24 pm

Now with all this attention, maybe Pacific Design Shops might be convinced to produce more depressed center car kits.

Terr1bleone
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Re: Depressed center flat car

Post by Terr1bleone » Fri Jan 07, 2022 7:01 pm

Russell, I agree the table saw should have been square and consistent, I believe it was the human operator error. I would have liked to have helped the cutting and check boards as they were made but unfortunately that wasn’t the case. I would say that an average of 12 thousands over wasn’t bad for a tape measure, some were much worse, or tapered. as for the ends being out of square I’m not sure, possibly the boards were stacked while being cut and shifted? I do believe it was a “rushed job” so that adds into it.
Carl, the length normally wouldn’t be as important but as the hole pattern is already in the metal deck, the boards won’t fit if I go drilling the patterns in them by measuring from the ends. Thank you to both of you for noting the swelling factor, the humidity in my shop right now is about 20% so I will have to factor that in now. The boards were already done a few thousands under to account for the stain thickness. I’ll probably drill them all while they are properly sized then back into the mill to cut maybe ten thousands off each side plus finish sanding. Carl, I see that you used hex head bolts instead of button Allen heads, what size did you use?
Howard, I believe that John still has a few kits available, you’d have to contact him to see.
-Mike

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ccvstmr
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Re: Depressed center flat car

Post by ccvstmr » Sat Jan 08, 2022 10:37 am

Terr1bleone wrote:
Fri Jan 07, 2022 7:01 pm
Carl, the length normally wouldn’t be as important but as the hole pattern is already in the metal deck, the boards won’t fit if I go drilling the patterns in them by measuring from the ends. Thank you to both of you for noting the swelling factor, the humidity in my shop right now is about 20% so I will have to factor that in now. The boards were already done a few thousands under to account for the stain thickness. I’ll probably drill them all while they are properly sized then back into the mill to cut maybe ten thousands off each side plus finish sanding. Carl, I see that you used hex head bolts instead of button Allen heads, what size did you use?
-Mike
Mike...believe I ended up taping the deck planks to the car frame. Flipped the car over and used an awl to transfer the hole locations in the metal deck to the deck planks. Then, drilled and counterbore the top. The counter bore had to be large enough to get a hex driver to tighten the screws. Probably removed wood burrs from the underside too. Used the same method when doing the planks on the bulkheads as well. Come to think of it, might have drilled over-sized holes in the planks to allow a little "wiggle room" when installing the deck. Last thing you want is to be fighting small screws...and a lot of small screws!

Made my planks 3/8" thick. Purchased stainless steel, 4-40 x 1/2", hex head screws from either Microfastener or Albany County Fastener (ACF might have a minimum dollar purchase order amount these days). Used stainless washers under the screw heads. Those were either #4 or #6. Sorry...too long ago to remember.

As long as the deck boards fit loose side by side...expansion shouldn't be much of a problem. If you find some boards that are tight...can run the side of the board by a belt sander or pass it thru the table saw again and take a light skim cut off the plank sides. You'll be fine after that. Carl B.
Life is like a sewer...what you get out of it depends on what you put into it!
I don't walk on water...I just learned where some of the stepping stones are!
I love mankind...it's some of the people I can't stand!

Terr1bleone
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Re: Depressed center flat car

Post by Terr1bleone » Sun Jan 09, 2022 1:03 am

The boards seem to fit with slight gaps now so that’s good, I went on to finishing them up.
I would have liked to use carls idea of temporary attaching the boards and transfer punching the holes but the frame is in the way.
Simple setup to drill the deck boards.
I was adamant on getting the boards to be consistent in width so that the setup on the vise position can be set and forget. I thought about making a jig but the mills digital readout seemed easier. I had a center drill that was sized the same diameter as a 5-40 thread. I was using 4-40 screws so that gives me some wiggle room.
You can see the counterbore on the vice, also for 5-40.
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After that I used the supplied extra deck to transfer the middle holes easily, a #30 drill was used.
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One side done minus finishing work and stain/sealer.
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-Mike
Last edited by Terr1bleone on Sun Jan 09, 2022 11:59 pm, edited 1 time in total.

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makinsmoke
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Re: Depressed center flat car

Post by makinsmoke » Sun Jan 09, 2022 12:11 pm

A lot of decking I’ve seen is ship lap.

Specifically floor boards for Santa Fe stock cars.

Ship lap would give you ample expansion and contraction, and keep the closure between top and bottom.

Truck and trailer decks not so much. Contemporary anyway. I can’t speak to early through say the 40’s. It’s certainly cheaper to cut four edges on a length of wood versus eight.

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