Any of you guys have experience with arched extension jambs.
Situation is pine staingrade windows and i am adding 3/4″x 3″ clr pine jamb extensions.
there are two aproximatly 36″ radius wndws that need the same furring out.
My plan was to rip some 1/4″ x 3″ply and clamp it to the proper radius .
Then get some iron on veneer (?) and attach to the two exposed sides of the ext. jambs.
Hope that makes sense. If not any ideas.
Thanks.Greg
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Replies
Greg
My plan was to rip some 1/4" x 3"ply
Is your plan to rip plywood and try to add to the current jamb on the same plane? Why not add on like a typical jamb extension - using a revel.
I would use pine for my strips and glue up as you suggested in your post, but install it like a typical extension and leave a 1/8 or 1/4" revel. No need for the veneer if you start out with the right wood.
Doug
Edited 8/15/2007 10:53 pm ET by DougU
Ya.
There is a typical reveal. So some 1/4" pine rips will bend that 36 3/16" radius?
If so sounds good.A little worried about the yellow glue setting up too fast,any suggestions there?
Should i kerf it or soak it or no worries on the 3" x 1/4" rips? or just do it.
Hey,That guy stole my name.
Just do it. That'll be fine.
Mike
Thanks.
36" isnt that tight is it.
I like to worry.
>> I like to worry. - Sounds like my in-laws. Man they worry about everything.
Anyways, good luck. It'll be a piece of cake.
Mike
Edited 8/15/2007 11:51 pm by arcticcat
fish
You can try the 1/4" rips but they could potentially be a little to thick, I think Hammer mentioned 3/16ths, probably better.
I don't worry about yellow glue setting up to quick on a simple bend like this. someone else mentioned UF glue but I doubt you need it in this application. You can afford some spring back on this deal, easy enough to bend and fit as you apply.
See the jig in Hammers post. If you glue up your pieces you wont have open time of more then a few minutes - more then enough time to get the wood in the jig and clamped up.
One other suggestion, when I bend something like this I will rip my strips 1/4" wider then your desired finish width, glue up and then joint one end and run it through the saw for final sizing. That way you don't have to worry about getting the wood even in the jig.
NO soaking of wood is necessary either!
Doug
Edited 8/16/2007 12:27 am ET by DougU
Thanks for sending me in the right direction.The whole veneer thing wasn't feeling to good.Was thinking about using some blocking as opposed to burning up 3" of ply for the jig.
I'll try a fat 1/4' rip on the inside radius so the casing will hide the glue line. We'll see. I can always go smaller.
Thanks bro.
Was thinking about using some blocking as opposed to burning up 3" of ply for the jig.
For a quick jig, and thats all this one has to be, I have taken 3/4 ply blocks - maybe for your project a 4" X 4" would sufice, and pocket screw them to the work bench, or a piece of plywood in the radius that you desire.
Bend your pieces around the blocks(or to the inside if thats the way you laid them out) and clamp in place. Presto, your done.
Make sure you add a little to the length so that you have some trimming off material, sucks when you come up short!
Doug
sounds good.
No jointer and no pocket jig , but there on my list.I"ll make it work.
I guess I'm not just a framer anymore.Shoot
The extension jambs are usually laminated out of thin strips of solid wood. 3/16" is about the thickest you will want. A urea resin/plastic resin glue will give you time to work I have a pic of a form I made for the casing which was sawn but beading was bent around inside and out. You'll get the idea, the extension form is the same only thicker. Don't worry too much about springback, there is a certain amount of flexibility to the arch, but not a lot. You may also find that the arch is not a true half circle, it actually straightens out for a few inches on the ends. Bendable plywood may be another option, I haven't tried it yet for extensions, sometimes called "whacky wood".
Beat it to fit / Paint it to match
Thanks alot for the feedback. Really helpfull,I think I'll bill out a couple hours for you and dougu.
I might have some wacky tobacky in the garage,but never had much luck with that stuff while working.Would probably swing a nice arch and end up cutting it short or something.
thanks again for the heads up.
You are much better off with laminated jambs. It sounds easy to make, but can waste a huge amount of time.
1/8" thickness for each layer is what I'd shoot for. You might want to lightly mist the wood to keep the glue from setting so fast.
I'll also warn about not getting the laminations right. Any twist or bow in the lamination will be much harder to correct for than if it were solid wood because of the strength of the lamination. It will also want to spring "open" so build your form a little tight, although you could make it work without allowing for spring back, it's just easier if you do.
You can also order what you need from one of the various specialty trim outfits, and even many window manufacturers do this in house. We simply order them with the windows.
Good luck
Beer was created so carpenters wouldn't rule the world.
Thanks for the info on the spring back.
So if u were shoot ing for a 40" inside radius what radius would you make your form?
I'd make the inside radius 39-1/4", but I have a book somewhere with an article written by an outfit that makes a bunch of laminated parts and they have a formula they use based on a few variables. I'll bet you'll still have some spring back at 39-1/4"r but you'll be close enough to make it work. If you search the archives there is probably a better rule of thumb in here somewhere.
For instance the last arched jamb extension I installed was formed at exact window dimensions and had about 1/2" of spring on each side for a 16" radius window (it opens up to about a 16-1/2" radius) and red oak for the material.
The layers of the laminate are harder to keep together than one would think, so if your first attempt doesn't work so well, make a complete half circle form from layers of mdf and do it right with lots of clamps. If you are on a tight schedule don't put all your eggs in one basket and assume your first attempt will work.
Best of luck
Beer was created so carpenters wouldn't rule the world.
Thanks.
I'll make it work .
I'd make the inside radius 39-1/4",
Don, I cant count how many times I've made radiused pieces but making a piece of jamb extension thats supposed to be 40" radius 39 1/4" isnt going to make any difference in the world.
I could make that jamb extension using a 50" radius jig and you'd still be able to bend it to the 40" that you need. Same as if I made it 30" and you needed 40". Taking 3/4" off a jig isnt going to change anything, its doubtful that the piece will come out of the jig in the exact same radius that you need and it doesnt have to, the piece will bend to the needed radius.
I'm not dissing your recomendation just letting the OPer know that for jamb extensions it's not going to have much berring if the piece springs in or out from the intended radius.
Doug
Why don't you go to the window company and order them made for your windows? other alternative would be to have a millwork shop make them for you..... worth the time & $$$$$
That's really the best way to go unless a guy just wants to try to laminate one.
Beer was created so carpenters wouldn't rule the world.
Because I am carpenter,and enjoy my craft.
I like to ask questions,sometimes i know the answers but i still ask ,There alot of different ways people do things.
I like to put myself to sleep building something in my head, that i need to build next week.Visualizing different techniques.
Did you see hammer1's setup.Glad i asked. done
Edited 8/17/2007 9:39 pm by fishdog