Steamin plywood to shape & Yatton VoF build

Fred2179G

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I use battens along the sides, a paint pot, and some strong bungee/elastic cords. I soak the plywood in hot water for an hour or so, and then leave it bent for about 2 days until it is thoroughly dry. (This is the roof of a small Ozark caboose. It has a hole for the cupola, and another small roof section for that.)

20200330_112258_roof-prep.jpg
 

FrenchChuffed

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I only just caught this thread. Basically it started off on the incorrect premise you don’t steam plywood. If you want a curv in plywood you laminate it yourself from thin bits of wood or what is known as bendyply it has the grain mainly going in one direction. If the end result is required to be thin like your roof then you have to start off with thinner to make up at least 3 ply (at 90 degrees to each other) glued and held on a former to the required shape.
 

FrenchChuffed

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Well unless the plywood is very thin like 1/16 or a mill or so and it will bend easily without strapping it down with a 10 ton weight lol
 

Greg Elmassian

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1/16" is .0625, one mil is .001" so I cannot make sense of the wide variation in the numbers you quote, clearly anything one thousandth of an inch will bend except for glass.... ;)

The very first post specifies the thickness, and the recommendation from the manufacturer of the kit...

So, again, are you saying that the manufacturer is misleading people in that the plywood of the specified thickness cannot be bent?

Maybe you can help the manufacturer and straighten them out?

If you haven't gotten the point, clearly someone was able to steam the plywood and bend it...

you can bend even thicker wood, given a steam cabinet and the right forms.

Tom_Raffield_Low_Res218.JPG


Greg
 
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FrenchChuffed

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No need for a silly rant, i have bent 40mm thick iroko 200 mm wide fresh out of a steam Cabinet but we are talking about plywood which by its nature is cross laminated and made to be flat so there is a limit to the stretchability of the outer skin.
 

Greg Elmassian

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The way I bent ply for a curved roof was to;
a. Wet it with warm water.
b. Wrapped it around a tinned fruit can former, it did not bend much, and secured it with strong elastic bands.
c. I filled the can with boiling water and kept checking the temp periodically and adding new boiling water to the tin as needed as well as keeping the ply damp all the time. If the ply was warm on the outside it meant that the heat was all the way through.
d. Repeated this process over a few days till the desired shape was achieved allowed ply to dry and when t "sprung out a bit" I repeated the process.

I only did this once; the next time I used balsa wood, using the same former, which bent far easier and quicker just had to be more careful on the stress I applied.

My neighbour, who was a wood worker, told me that the type of glue used to make the ply has a big influence on how easy it bends due to its softening properties.
 

Paul M

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Whack it in the microwave to soften the glue, if you can do that wrapped round a non metallic former it should work
 

maxi-model

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Whack it in the microwave to soften the glue, if you can do that wrapped round a non metallic former it should work
At what power setting, dependent on wattage of appliance, for how long and what would be the best material for the former would you recommend ? I think we are getting into a whole new realm of thermodynamics here. Sorry Paul, I'm just being a bit naughty now. Max
 

maxi-model

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I only just caught this thread. Basically it started off on the incorrect premise you don’t steam plywood. If you want a curv in plywood you laminate it yourself from thin bits of wood or what is known as bendyply it has the grain mainly going in one direction. If the end result is required to be thin like your roof then you have to start off with thinner to make up at least 3 ply (at 90 degrees to each other) glued and held on a former to the required shape.
Yep, I get that. I think I was going down that route in my head in post #10. Only I would have used two layers 0.5 mm laid with the grain the same way, longitudinally. See the next "postscript" Max
 

maxi-model

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Postscript

So, things have come to pass. At the same time as I originally posted this topic I also emailed the maker (late on a Saturday evening). The usual thing.......HELP ! (In a polite constructive manner). Well, first thing on Monday morning I get a phone cal from them, apologising for not getting back to me on the Sunday (now that would be service). Seems as though they came to the same conclusion as to a solution as I had thought about too. "I have produced a set of roof panels for you, still with the etched detail, that are 0.5 mm thick rather than the 1.6 mm supplied. Will that do ?" Too bloody right it will, merci buttercups me old mate. They arrived yesterday, and yes they are a thing of beauty, a testimony to the laser cutter's art and the answer to my prayers.

There was also a suggestion that the supplier had a suspicion that the his stock of (some) 1.6 mm ply might not have been to the spec' ordered or defective in some way. Hence possibly the pliability issues I was experiencing (every pun intended). Looking at them the grain pattern is most certainly not linear, at least on the top layer. My lack of knowledge of the whole steaming thing notwithstanding did not help either.

Morals of this story - be a little more patient, always be nice to those you will be seeking assistance from at all times, never be afraid to ask (because you might not get if you don't) and think outside of the box (was I even asking the right question for starters).

Ho hum, lessons learnt but a wealth of data created here for those having the same issues in the future. I think there is a reason that in the many years of building ply kits the whole steaming pile.........sorry my finger slipped, steaming ply to form it to shape has never reared its head before. The whole process looks a PITA and one to be avoided at all costs. Which is why every other maker has probably engineered their kits otherwise when using this material. Max

P.S. Full disclosure of what is being built here will be posted in good time with the revelation and fulsome praise of the kits maker.
 

Paul M

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At what power setting, dependent on wattage of appliance, for how long and what would be the best material for the former would you recommend ? I think we are getting into a whole new realm of thermodynamics here. Sorry Paul, I'm just being a bit naughty now. Max
I must admit to doing this with thinner ply, but I think it was a case if trial and error, so ran it 30 seconds each time until it was warm enough, rather than put it straight in at 2 minutes or so.
Please no, I accept no responsibility for ANY marital discord this may create
 

maxi-model

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I must admit to doing this with thinner ply, but I think it was a case if trial and error, so ran it 30 seconds each time until it was warm enough, rather than put it straight in at 2 minutes or so.
Please no, I accept no responsibility for ANY marital discord this may create
Now entered in book of useful microwave recipes. It'll make a change from the odd Tesco Finest ready meal. Mmmm, that 1 mm birch ply has a really nice chewy texture, with a bit of a satisfying initial crunch as you bite in :D

Seriously Paul, I'll give it a little try sometime. It sound a very handy tip. I've got some of the 1.6 mm stuff lying around here spare somewhere. I can't think why ? And other sizes too. I've done the soak in hot water and fit to former bit, with the ply scored on the backside, with thicknesses 1 mm and below. Max
 

Paul M

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Postscript

So, things have come to pass. At the same time as I originally posted this topic I also emailed the maker (late on a Saturday evening). The usual thing.......HELP ! (In a polite constructive manner). Well, first thing on Monday morning I get a phone cal from them, apologising for not getting back to me on the Sunday (now that would be service). Seems as though they came to the same conclusion as to a solution as I had thought about too. "I have produced a set of roof panels for you, still with the etched detail, that are 0.5 mm thick rather than the 1.6 mm supplied. Will that do ?" Too bloody right it will, merci buttercups me old mate. They arrived yesterday, and yes they are a thing of beauty, a testimony to the laser cutter's art and the answer to my prayers.

There was also a suggestion that the supplier had a suspicion that the his stock of (some) 1.6 mm ply might not have been to the spec' ordered or defective in some way. Hence possibly the pliability issues I was experiencing (every pun intended). Looking at them the grain pattern is most certainly not linear, at least on the top layer. My lack of knowledge of the whole steaming thing notwithstanding did not help either.

Morals of this story - be a little more patient, always be nice to those you will be seeking assistance from at all times, never be afraid to ask (because you might not get if you don't) and think outside of the box (was I even asking the right question for starters).

Ho hum, lessons learnt but a wealth of data created here for those having the same issues in the future. I think there is a reason that in the many years of building ply kits the whole steaming pile.........sorry my finger slipped, steaming ply to form it to shape has never reared its head before. The whole process looks a PITA and one to be avoided at all costs. Which is why every other maker has probably engineered their kits otherwise when using this material. Max

P.S. Full disclosure of what is being built here will be posted in good time with the revelation and fulsome praise of the kits maker.
It's always worth discussing problems with a supplier or manufacturer, they should always prepared to help you out, even if it's to tell you where you're going wrong.
The microwave idea wasn't mine, not sure exactly where I picked it up from, might even have been from this forum
 

Greg Elmassian

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One of the links I supplied showed several methods of "steaming" and one used the microwave.

I think the key was talking to the manufacturer, either they have achieved it, or perhaps their supplier changed the materials and they did not re-test the manufacturing procedure.

Glad that they "made it right".

Greg

p.s. I learned a lot about making a steam box for wood, not as big a deal as I thought.
 

maxi-model

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As promised here is the subject in question with the 0.5 mm ply roofs fitted and being fitted. Yatton produced 16 mm scale model of The Vale of Ffestiniog rebodied Funkey.

20210619_071047.jpg 20210619_103135.jpg

I love this loco, its "face" is very reminiscent of the "Western" class 52 BR locos - one of the most aesthetically pleasing designs from the '60's era to my then child's eye. It also shares its hydraulic transmission system mthodology too. A hefty dose of "dog bone" is in there and a smidge of "shed" too. The kit as supplied is of all laser cut plywood construction with 3D printed details and gearbox casings, pre cut glazing and some 3M metal effect window surrounds. Insulated steel wheels are there as are torquey motors , with 40 : 1 brass gear sets (20 & 60 : 1 are available too as well as a 2 powered axle option) for each of the 4 axles.

It goes together well, however, there is a lot of work disguising the wood to represent the metal construction of the prototype - Rub down all the parts before assembly, 260 grit followed by 400. Then spray coat the subassemblies with 2 coats of a cellulose based sanding sealer, each rubbed down with 400 grit followed by 800. We will see now if I can get away without resorting to filler primer to get the required final smooth surface finish.

Interestingly, reading the instructions, suggests I could haveI could have ordered it (in part) MDF. A subsequent request elicited a partial set of body components in that material that I could have used to overcome some of the laborious processes described to hide the ply's wood grain. It is notable some suppliers are now offering kits as either/or ply/MDF. In part to offer a simple answer to representing metal bodied stock or, with a ply option, to offer an alternative to MDF to those resistant to this "new fangled" material (at least in this sector of the railway hobby) or where that material is more appropriate. This kit's supplier suggested a preference for production in MDF as it is a more stable material and easier to cut than ply. Of course, if some curvature needs to be applied the the use of ply is pretty much mandatory, with the aid sometimes of laser etched engraving. I think I have said enough now :D. Max
 

Greg Elmassian

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Glad of the success... to boil down the manufacturer's response, did they ever say the supplied material was really too thick for the average person to bend? Or is this possibly a new kit with not a lot of customer feedback?

In any case you got through it.

Greg
 

maxi-model

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Glad of the success... to boil down the manufacturer's response, did they ever say the supplied material was really too thick for the average person to bend? Or is this possibly a new kit with not a lot of customer feedback?

In any case you got through it.

Greg
Probable causes ? - May I direct you to the 2nd paragraph, post #32 Greg :). The kit's instruction sheets have the date 17/1/2015 printed on each page. I do not know if this aligns to the product's launch date or the date of this particular instruction set version's inception. The kit supplied appears to have had some minor revisions that do not show up on these sheets (but does not affect the build process) so probably the former. So, it has been around a while. In my experience Peter the proprietor (I'm sure there's a TtTTE character there) seems to be very receptive to constructive feedback (i.e. from busy body know it all's like me:D) when offered. So, I would think his offerings get debugged, if necessary, fairly quickly. Then again, those of us who have engineered kits all have our own way of doing things and sometimes nothing will shift us from our convictions. Been there done that and learned the lesson.

If you model the Welsh Highland Railway, and have need to haul a very heavy rake of 5/6 of their typical coaches, a loco like this is quite handy to have......... if you do not want to steam your Accucraft NG/G16 (OK, now I am just showing off ;)) Max


The real thing with WHR stock. You will have to play back on YouTube
 

maxi-model

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Little tryout for the layout of the internal gubbins for the Funkey - Battery pack, RX, ESC, MLS soundcard, speaker, motors, switchgear, charging jack, wiring loom, prime mover......Prime mover !? Well there is sooo much empty space under the hood(s) on this loco it just had to be done. Needs a fair bit of balancing weight over radiator end too, lead flashing to hand. A very Funkey loco indeed, perhaps ? ;) Max

20210620_163532.jpg