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Forum topic by wannabenorm posted 786 days ago 1088 views 0 times favorited 19 replies Add to Favorites Watch
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wannabenorm

33 posts in 807 days


786 days ago

Topic tags/keywords: help tip question

im currently working on a train bed for my three year old son (or caboose) and im trying to get a rounded top on it like the real one and im having trouble getting 1/4 birch to bend like i want it ive soaked it with water hose and keep trying to put more pressure on the pipe clamps to get it to arch and done ruined one piece all i have to work with are the basics skilsaw, jigsaw,router small band saw and nail guns oh yea orbital sander most which i purchased as needed any tips would be grateful for or am i doing all i can with what i have to work with?

-- if i say something stupid over look me im learning.....


19 replies so far

View a1Jim's profile

a1Jim

109273 posts in 2078 days


#1 posted 786 days ago

A photo might help but if your trying to bend birch try very hot water or cutting two 1/8” strips soak them in hot water and clamp them in the shape you want ,then let them dry a couple days or more depending on the how warm and dry it is their drying in, and then glue the two rings together to make a 1/4”.
Or go to plan “B”
and use your router on a home made trammel and just cut the arch out of solid wood.

-- http://artisticwoodstudio.com Custom furniture

View wannabenorm's profile

wannabenorm

33 posts in 807 days


#2 posted 786 days ago

the bed is 75 inches long so i was wanting the top to cover the whole bed

-- if i say something stupid over look me im learning.....

View a1Jim's profile

a1Jim

109273 posts in 2078 days


#3 posted 786 days ago

It seems like a quarter inch might be to thin .I would go with several strips of wood laminated together it will be stronger than one solid piece.

-- http://artisticwoodstudio.com Custom furniture

View levan's profile

levan

382 posts in 1480 days


#4 posted 786 days ago

You might try cutting kerfs with your skill saw or router with a straight edge in the bottom side of the ply. Try it on a scrap, to see how close together and how deep you need them to make the bend. I would think maybe 1/16” deep and maybe 1- 2” apart. You don’t say how wide the bed is but the kerfs should run the length.
best wishes

-- Lynn "If you think you can do a thing or think you can't do a thing, you're right". Henry Ford

View 404 - Not Found's profile

404 - Not Found

2544 posts in 1470 days


#5 posted 786 days ago

Is this what you need to make – like the roof of the engine cabin?

View wannabenorm's profile

wannabenorm

33 posts in 807 days


#6 posted 786 days ago

yes the bed is about 38 inches wide and 75 inches long and renners thats excatly what im looking for to try to get it to do

-- if i say something stupid over look me im learning.....

View PurpLev's profile

PurpLev

8473 posts in 2149 days


#7 posted 786 days ago

are you clamping this to a form? or just trying to bend it by clamping the 2 edges and pulling them to one another?

the first option would be the ‘correct’ way as it will pull the wood down into a round shape which will also back it and prevent cracking, the later option does not provide any support for the fibers and at some point it’ll just snap.

I recommend searching online and in libraries about wood forming/bending. and like Jim said – it would probably be easier if you had thinner slabs and laminate it yourself than using an already laminated 1/4” material as the glue between the layers is already set to keep it sort of flat. not impossible though…

good luck

-- ㊍ When in doubt - There is no doubt - Go the safer route.

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Sarit

453 posts in 1640 days


#8 posted 786 days ago

You have to cut kerfs like levan said. The alternating grain in the plywood layers makes it hard to bend. You have to cut through almost all but the top layer to make it bend.

Or find bending plywood like this:
http://packardforestproducts.com/products/plywood/hardwood-plywood/bending-plywood/

I usually hear about steam bending. I’m not sure if hot water will be enough to get plywood to bend. If it does work, you will want at least 2 layers of plywood glued together after bending so that the curvature is maintained.

View 404 - Not Found's profile

404 - Not Found

2544 posts in 1470 days


#9 posted 786 days ago

The trouble with laminating thinner material together to form the arch (especially plywood) is you’d probably end up with voids in it. You’re limited as well by the tools available to you.
No matter which way you go, you need to have shaped ribs to fasten the sheet material down to.
I would do it like this,
2 sheets 1/4 inch mdf, put kerf cuts 1/8” deep into the sheets every 1/2 inch (make a jig like this for the skilsaw)

Then laminate them together – kerfs inside – over the ribs using a paint roller to put a good coat of glue on.

Best try it dry first and have plenty of cauls and cramps to hand.

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a1Jim

109273 posts in 2078 days


#10 posted 786 days ago

I thought you were talking about the edge of the round top. I think Renners has a good approach.

-- http://artisticwoodstudio.com Custom furniture

View wannabenorm's profile

wannabenorm

33 posts in 807 days


#11 posted 786 days ago

i was just trying to pull them together with no form i have a piece of mdf with a grove rabbited in it for the form to go in once i get it to the correct width on each end and thanks for the help guys im no expert in woodwork by no means just a man trying to get the things my kids want and satify myself by doing so

-- if i say something stupid over look me im learning.....

View wannabenorm's profile

wannabenorm

33 posts in 807 days


#12 posted 785 days ago

oh yea i have a biscuit cutter its the samall one and a kregg jig kit iwas thinking of cutting some 3/4 strips the length of the bed and bevel them 5 degrees and bisuit them together and glue and just keep adding till i get the width across and then sand top till got round how does this sound i was just wondering if that would work or too much work

-- if i say something stupid over look me im learning.....

View dhazelton's profile

dhazelton

1101 posts in 797 days


#13 posted 785 days ago

Since you say ‘birch’ that leads me to think you plan on a natural finish. If you go paint grade you definitely have more options like MDF, luan or masonite. I’d go 1/8” and the material should bend fine. I know you want to do something you’re proud of, but remember that in a year you may be changing this bed into a rocket ship or race car. I would just go simple and inexpensive.

To point, I spent three days painting a client’s childs bedroom once to look outer space – medium blue walls, dark blue ceiling with dayglo star systems, red trim , rocket ship painted on one wall, taking down the ceiling fan and spraying to match. I went back a year later and they had repainted everything with two coats of Kilz primer as the kid was into the movie Cars and they were gonna follow suit.

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wannabenorm

33 posts in 807 days


#14 posted 785 days ago

im going to paint it since the other things on it that are round are out of mdf and basically was all i had to work with without spending alot of money on more materials to do it with ill have to post pics i guess so everyone will see what it is im working on

-- if i say something stupid over look me im learning.....

View Danpaddles's profile

Danpaddles

530 posts in 813 days


#15 posted 785 days ago

bendable plywood, of course. Too bad you are so far from Indianapolis, I have a sheet I am looking to get rid of.

http://www.woodmagazine.com/materials-guide/lumber/sheet-goods-selector/?page=4

-- Dan V. in Indy

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