wax to stop glue sticking?

[ecks79]

Hi guys.

Im trying to stop lams from sticking to the form, from the squeeze out. i've been told wax is ideal - is there a specific wax? what should i be looking for? or can i literally grab a candle and drip wax on it?

sorry, probably a stupid question but i have been looking and can't find anything...

Thanks!

T

[Skew ChiDAMN!!]

Dripping?

Not quite the same situation, but I have used plain wax candles like crayons and simply "coloured in" the areas I didn't want glue (or finishes) to stick to.

[ecks79]

Dripping?

Not quite the same situation, but I have used plain wax candles like crayons and simply "coloured in" the areas I didn't want glue (or finishes) to stick to.

Thanks Skew.

I was going to light the candle and drip it on the form so that it soaked in... can the wax be lightly sanded away from the contacting timber once it comes out of the form? seems pointless to wax up the form, only to get it onto the final face of the timber - if the finish won't stick...

[Skew ChiDAMN!!]

As I said, I haven't used it in your situation. I think.

I often clamp waste blocks in position as "temporary formers" and wax these so they don't stick after unclamping. I can't say I've ever had any real problems with removing any wax off the finished surfaces.

But are you cold-pressing the laminates or steaming/heating them first before clamping them in the forms? I'd imagine that if you're forming heated timber then there'd probably be significant wax transfer, enough to warrant more than a "light sand" to remove. :~

Sorry I'm not of more help... :B

[Manuka Jock]

I have used end sealing wax . The sort we put on the end grain of fresh cut logs .
The drawback in some steam bending situations is that , yep , the wax can transfer to the piece being laminated and stuff up further gluing and finishing .
The better way might be to line the inner side of the molds with a plastic strip

[Woodwould]

If laminating cold, then rub the side of a candle over what ever you don't want getting stuck.

If steam bending, then the heat will make the wax transfer onto the laminations. In that case, I would use polyethene sheeting.

[ecks79]

Hey guys!

Thanks heaps for your advice, i will be laminating... so no heat. Sorry i should have mentioned that.

I have been doing more research this morning, a few forums have been raving about baking paper... the type that is 'wax like' on one side... apparently it is also good to use.

Ill try both and let you know which works best :-)

Thanks again guys, greatly appreciated.

T

[Basilg]

Wax will work, I find it better to cover the former with packaging tape, that is the very fine stuff used for wrapping parcels etc., that will stop your glue and laminations sticking to the former. then you don't have to worry about wax transferring or whether the wax needs replacing.

Regards

[Master Splinter]

I was just about to say packing tape, too - at least thats what works for me when fibreglassing a subwoofer enclosure in a car boot!

[Rattrap]

I use Carnuba wax to stop glue from sticking to frames or cauls, works really well & is soft & easy to apply with a cloth & i have it in my cupboard. Bunnys sell is as well as many Mitre 10 & Home & hardware stores. :2tsup::2tsup:

[Wongo]

Any wax will do. Do you have a tub of Ubeaut wax?

[Rocker]

I use brown shiny packaging tape. It works fine.

Rocker

[ecks79]

Thanks guys! i gave it a go this weekend using some perafine wax?! (something along those lines) so we'll see by morning.

On the opposite end of the scales, what glue is best suitable for bent laminations? Unfortunately today i buggered $100 of nice cedar because the glue i was using dried before i could finish gluing up my lams :((. the glue i used was called bondcrete (recommended by a timber expert specifically for lams).

I was gluing up 9 x 2.5mm x 1.8 mtr lams, i used half a bottle (500ml), it still wasn't enough glue (no squeeze out) and it was dry by the time i got to clamping. That's what i call a mass fail:no:

Any ideas, education and anything else going would be greatly appreciated ;-):2tsup:

thanks guys!
T

[Manuka Jock]

T , Tell us a bit about the project that you are working on .
What is it , what is it intended for and what wood are you using .How tight is the radius , and what are the dimensions and how long are the timbers that you are bending ?

[ecks79]

T , Tell us a bit about the project that you are working on .
What is it , what is it intended for and what wood are you using .How tight is the radius , and what are the dimensions and how long are the timbers that you are bending ?

http://www.woodworkforums.com/attachment.php?attachmentid=148586&stc=1&d=1285488912

Hey - sorry MJ - i should probably have started with that.

I'm trying to replicate this image (link above), but in miniature - as a baby bouncer. I'm using WR Cedar, the radius of the bend is approx 2.5 - 3 inches and the total length of the lamination's (support legs) is 1.8mtrs, i am cutting the lams to about 2.5mm and prepping the bend with a slightly steamed timber to start - clamping it till it dries, then gluing up. the width of the lams are about 50mm and hoping to get them to 45mm after cleanup.

This is the first time I've tried this, and to be honest i thought I'd get it first go... so was a little disappointed after failing today. I don't have a jointer to square up the timber, or a thicknesser or drum planer - so once i have cut all the lams, i lay them out to make a wide sheet - then give them a light hand sand to minimise the ridges caused be the band saw.

A dry run prooves to be OK (as in no gaps between lams - not perfect)... but i it just takes too long to get the glue on all 9 lams before glue up.

Thanks, hope all this makes sense. I will post some pictures of it later in the week when i get a chance to swing by the shop. the half dried lams are still clamped - going to leave them till end of week and just see what the result is...

T

[Manuka Jock]

Ok , now do you have some photos of the work that you have done. The bandsawn timber , before and after sanding , the clamping system and the failed glueup ?

Also , look into this Bondcrete .
As far as I can see , it is primarily a masonry product . It also has a million more "uses around the home"
It is hardly a dedicated timber glue suitable for compound curve lamination woodwork .

[Rocker]

I use Techniglue epoxy for bent laminations for rockers and back slats. It should give you at least half an hour of working time, unless it is very hot weather - say, more than 30 C. Do not use PVA glues, which will creep under stress. Carbatec stock Techniglue.

I am a bit dubious as to whether WR cedar will be strong enough for your purpose. I would prefer to use a strong hardwood like blackwood or jarrah.

Rocker

[Rattrap]

I've never done bent laminations myself but i have looked into it a little as i plan to build a rocking chair with laminated rockers. For the rockers i have bought some Titebond long open time. Its rated for a 15 - 20min open time & is recomended by a top rocker builder. However your curve is pretty damn tight, it looks to me like a perfect job for steam bending. I visited a local artist a few months back who specialized in steam bent timber. He uses a polyurethane glue for all his lamination. His reasoning behind the poly glue is that while the glue isn't as strong as other glues when it comes to joints 'pulling apart', laminations tend to pull along their length or slide apart & this is where poly glues are especially good. I've seen heaps of his work, both indoor & outdoor & have never seen any sign of failure. Poly glues also have a good open time.
Good luck with the project, i love anything with sweeping curves in it & this should be a really nice project when finished.

[ecks79]

Thanks guys!

MJ - I'll be sure to get some photos on the weekend when im back in the shop, then post them up. I appreciate you taking the time to check it out! I also agree with the bondcrete, having looked into it myself. And it doesn't have the working time it claims - it took me 10 minutes tops from start to finish!

Rocker - thanks for the heads up! ill look into it... half an hour sounds plenty! and I understand your concern with the cedar, i had similar concerns, so last week i quickly glued up lams to make a thin bend (total of 15mm thickness) and it seemed strong enough - put two side by side and it should be plenty... but time will tell :C - i also have 2 lengths of Oak ready to go, but thought the cedar might be an easier timber to work while i get the hang of it. Pine was just nasty to work with!

Rattrap - thanks for the info as well, ill check out both these glues. They both sound like they are what i need. Good luck with your work as well... sounds like you have done plenty of the research!

My next challenge is to get my bandsaw tuned better than it is. I spent most of the weekend aligning, squaring off and balancing... I think i have the wrong blade for the job though!

Thanks again guys! post piccies shortly.

T

[Manuka Jock]

T ,
check out this page for the Western Red Cedar Wood Properties by Connected Lines (http://www.connectedlines.com/wood/wood74.htm)

[ecks79]

T ,
check out this page for the Western Red Cedar Wood Properties by Connected Lines (http://www.connectedlines.com/wood/wood74.htm)

Hey thanks! :2tsup:

[ecks79]

I use Techniglue epoxy for bent laminations for rockers and back slats. It should give you at least half an hour of working time, unless it is very hot weather - say, more than 30 C. Do not use PVA glues, which will creep under stress. Carbatec stock Techniglue.

I am a bit dubious as to whether WR cedar will be strong enough for your purpose. I would prefer to use a strong hardwood like blackwood or jarrah.

Rocker

Rocker/MJ

What do you use to cut your laminations? Bandsaw or Table saw?

Would you expect to get a clean cut from your bandsaw? to the point where you could go straight into glue up without putting your lams through a thicknesser or drum sander?

If not, what other methods would be available to clean up the cut if you didn't own a thicknesser or drum sander? would a simple sanding block and sand paper suffice?

T

[Rocker]

Ecks,
For my rocker laminations I used a table saw followed by a thicknesser. I think that, if you use a band saw, you would need to clean up the laminations; if you don't have a thicknesser, you could probably do the job with a jack plane. However, it would probably be better to use laminations thicker than just 2.5 mm, if you are going to plane them. I used 6mm laminations for my rockers, but they didn't have nearly such tight curves as your project.

Rattrap,
I would be very wary of using Titebond for bent laminations. As a PVA glue, it is liable to creep, and your bent lamination might delaminate in hot, humid weather. I have built a number of rockers using Techniglue, and found it ideal for the job.

Rocker

[Basilg]

WRC has its place and the best one is in the tree.:wink:

I would suggest using a hardwood and there are may that would do the job very well.

Your plan to cut the laminations on a bandsaw is a good one & if you can't get a good cut from your machine then you can always dress the surface a little with a handplane by clamping one end and planing away from the clamp to keep the wood in tension. I am assuming that after each cut on the bandsaw you will be dressing the timber before cutting the next lamination.

I have used both Titebond PVA and Techniglue epoxy for laminating. I much prefer the former as it is cheaper, is a lot easier to clean up, and you don't have to contend with the fumes.

Using PVA you have to get the glue on & the pieces onto the former as quickly as possible and things that can assist are

Lay out all your pieces and apply glue with a small roller
Use as few laminations as possible
Glue a limited number of laminations at a time.

I would suggest revisiting your project as 9 x 2.5 laminations is 22.5 mm thick & will be very stiff and very strong. There are many commercial chairs available similar to the design you have shown, & I suggest you have a look at those & how they are constructed. Obviously the welfare of baby needs to take priority here, but I think you can safely reduce the number of the laminations and make the project a lot simpler.

Regards

[ecks79]

Thanks guys!

Both very useful comments and feedback. I think my biggest mistakes where, glue & timber selection, and trusting the bandsaw could give me a clean enough cut to go straight into clamping.

Basilg - I didn't dress the timber each time before cutting the next lamination, i will try that, i need to invest in a good hand planer - since i don't have the space for a jointer. any suggestions? one that will help me keep a square edge?

I do have a festool router table, the i can offset one side of the fence - i assume this could act as a planer in a similar way? - won't help me for each lam, but will help me prep before each cut?

regarding glue, i'd prefer to use one which is safer for the little fella - so will look into which is non-toxic etc. but obviously has the strength required.

Cheers guys - ill keep chipping away with all the suggestions. I've also found further ways to fine tune the bandsaw for a cleaner cut.

T

[ecks79]

quick update: Had someone at the shop un-clamp and put the cedar lams under strain... apparently stiff as a board and holds up great... although as Basilg pointed out, requires too many lams and is not practical. also, long term use may show differently.
Nice to know it would have worked though...

[Manuka Jock]

T,
I use the machinery at the club . Ripped with a bench saw and then thickness them.
I ran a few thru the bandsaw and found that it took a few more passes to thickness them . That may be due to the state of the bandsaw that does more circle cutting of lathe blanks than anything else.

[Basilg]

T

It is a bit difficult providing advice when I don't know a great deal about your experience or what tools you have. However I will assume minimum for both. On the handplane topic I would suggest starting with a fore plane which is a very versatile plane and capable of doing the majority of what you would require. There are many options ranging over a large price range one that is good quality and around the middle price range is the Lee Valley plane if you are close to a Carbatec store you could also look and purchase from them With the favourable exchange rate there would be a price advantage buying direct from LV. I would also recommend you buy one with an O1 steel blade which is easier to sharpen and IMO gives a better cut than A2.

Lee Valley Tools - Important Announcement (http://www.leevalley.com/US/wood/page.aspx?p=49708&cat=1,41182,52515)

There is a lot of information available on Bandsaws setting them up and their use, and this can be found in books, magazines and on the net. one source of this info and much much more is Fine Woodworking magazine. Michael Fortune is one guy that has written a fair bit on the subject. You can get a subscription to the magazine and or the online system or run a trial for a few weeks for free.

Fine Woodworking - Search: michael fortune bandsaw (http://www.finewoodworking.com/search/search.asp?cx=009096020989677304441%3Ayn5icbkse5w&cof=FORID%3A9&ie=UTF-8&q=michael+fortune+bandsaw&sa.x=23&sa.y=14&sa=Search&siteurl=www.finewoodworking.com%2F)

regards

[ecks79]

Thanks Basilg,

My experience is certainly limited, something i have not done in 12 years and just getting back into things.

I appreciate your advice and comments, they have been very helpful. I also got myself a subscription to fine woodworking, where i found a link to a youtube video. I might look for more from Michael like you've suggested.

In thinking about it, i also decided i may be able to use my router table as a Jointer for cleaning up the edges after each bandsaw cut, then change the setup to make the router table a thicknesser - using a straight cut bit - to run the 2mm lams through.

Im off to check out Lee Valley - thanks again!:2tsup:

T

[malb]

Bondcrete is essentailly a masonary glue as previously suggested, primarily used where you need to bond a skim of concrete to an existing cured slab, e.g laying slate or tiles in a mortar bed. Very good at this type of work, or as a waterproof seal coat over cement.

It is also very good for providing a very water resistant bond for woodworking, providing that you can cope with a few limitations. The first, as you discovered, is limited drying time. This can be extended considerably (doubled) by thinning the glue to about 4 parts glue and 1 part water, at the expense of also doubling the cure time. A reduced bond like this will not be as strong as a full strength bond, but would be still be as strong as the parent timber.

The second limitation is that it reacts with tanins to produce a dark stain through the penetration zone, which cannot be sanded or planed out to hide the seams. A third limitation is that the glue is rather heavy in the cured state, and a forth is that is promotes rust in any steel that it contacts in cured or uncured state.

When I was a kid my father built his third boat , a 22foot speedboat with twin Ford V8 flatheads. This was planked in 8inch x 1/2 inch Mahogany screwed and glued with Bondcrete as it was the most accessable water resistant glue available to him at the time. When the boat was about 15 years old, the boat was partially dismantled to convert to stern drives.

This involved shifting the motors to the rear, replacing the transom with a substantually thicker unit and reforming the hull over the last four hull frames to add about 12 inches to the transom width at the waterline to better support the increased stern weight. It proved impossible to mechanically seperate the planks from the frames and stringers after removing all of the screws in the area, with all attempts splitting the planks almost midway through their thickness. This gives some indication of the penetration and bond strength achievable with Bondcrete. The task was eventually completed by cutting out the planks and stringers and taking about 3/16inch off the frames where they had been in contact with the planks.



In thinking about it, i also decided i may be able to use my router table as a Jointer for cleaning up the edges after each bandsaw cut, then change the setup to make the router table a thicknesser - using a straight cut bit - to run the 2mm lams through.



It is relatively easy to set a reasonable router table for jointing the laminations, but to truly thickness them you would have to the laminations pass between the bit and the fence, which is generally considered as unsafe.

[ecks79]

Hey guys,

Thanks for all your help so far! Pictures below as promised... with a little more success and progress than this time last week.

IMG_0465.jpg (http://www.woodworkforums.com/attachment.php?attachmentid=149114&stc=1&d=1286088629) - the form
IMG_0464.jpg (http://www.woodworkforums.com/attachment.php?attachmentid=149115&stc=1&d=1286088629)
IMG_0466.jpg (http://www.woodworkforums.com/attachment.php?attachmentid=149116&stc=1&d=1286088629)

- Above - This is the form which i am bending the wood over. Last week i attempted to bend approx 9 x 2.5mm cedar strips, which i used boiling water on at the sharpest radius point - to get it all the way there.

IMG_0467.jpg (http://www.woodworkforums.com/attachment.php?attachmentid=149117&stc=1&d=1286088915) - failed bend using WRC
IMG_0468.jpg (http://www.woodworkforums.com/attachment.php?attachmentid=149118&stc=1&d=1286088915)

- Above - After gluing with bondcrete, leaving for 24 hours and unclamping, there was no movement (bounce back) in the radius or bend, however one week later, you can see form this picture what happened. Completely changed shape and opening an arch on what was supposed to be a flat base. Major spring back on the upper side also.


I have since used this piece to practice my edge cleanup methods and finishing up... which i'm happy to do on the router with the infeed fence set to .2mm

IMG_0456.jpg (http://www.woodworkforums.com/attachment.php?attachmentid=149120&stc=1&d=1286089411) - 50.8mm flush cut bit
IMG_0457.jpg (http://www.woodworkforums.com/attachment.php?attachmentid=149121&stc=1&d=1286089411) - .2mm offset in-feed fence

IMG_04601.jpg (http://www.woodworkforums.com/attachment.php?attachmentid=149134&stc=1&d=1286090491) - blade (upside down)
IMG_0454.jpg (http://www.woodworkforums.com/attachment.php?attachmentid=149123&stc=1&d=1286090491) - Finished surface (upside down)
IMG_0458.jpg (http://www.woodworkforums.com/attachment.php?attachmentid=149125&stc=1&d=1286089411) - Finished surface

- above - This weekend i got a new carbide tipped bandsaw blade, tuned her up and started ripping 2mm strips off a nice block of Oak and Jarrah, making sure i cleaned up the previously cut surface on a router table - setup as a planer - before cutting the next strip. This proved to be effortless and i'm stoked with the results. I then cleaned the remaining faces with the same setup (router table setup as plane) but using a backing block behind the 2mm strips for support.

Im now ready to start bending the Oak and Jarrah around the form, but found that the 1.5mm (net dimension after planing) lams still need some slight steaming to get them the rest of the way without splitting - but i didn't want to go any further with glue up until i found out if the steam/heat bending is what got me in to trouble with the previous attempt - the timber springing back and completely out of shape.


IMG_0455.jpg (http://www.woodworkforums.com/attachment.php?attachmentid=149126&stc=1&d=1286089686)
IMG_0465.jpg (http://www.woodworkforums.com/attachment.php?attachmentid=149114&stc=1&d=1286089993)

-above- this is a picture of the Oak going around the form. This is as far as it went before the lams were about to split/snap. So I steamed the lams very slightly and managed to get them around and dry clamped without any drama. I have also provided a picture of the lams and where they naturally spring back to once un-clamped (in the background). There is a lot of force required to get them tot he form, so my concern is that once glued, and un-clamped after 24+ hours... ill end up with a badly shaped bend...

Can anyone shed light on that? sorry, probably a stupid question!

For those who haven't seen it, this is the chair which i am trying to make (below), and the form i've made is to replicate the 2 legs...

Bouncer21980Lg.jpg (http://www.woodworkforums.com/attachment.php?attachmentid=149135&stc=1&d=1286090684)

Thanks to everyone who has offered assistance to date, you've been a great help... it has been many years since i've touched tools and timber and i think i've chosen one of the harder projects to get back into it :-) :2tsup: why do things in halves.

T

[Rocker]

I don't think you will get much springback if you use Techniglue epoxy to glue the laminations, although I must admit that I have not tried glueing nearly as tight a curve as yours. However, it is not going to work if you have to steam the wood. You may perhaps find, though, that the laminations are less liable to splinter once the epoxy is on them and has soaked in a bit. I think the job would be easier if you made a second former, so that the laminations are sqeezed between the two formers.

I still think the easiest way to stop your laminations sticking to the former is to line the former with brown packaging tape. I suspect that wax would just soak into MDF, so you would have to use a lot of it. It only takes a couple of minutes to stick the tape on, and the job is done.

Rocker

[ecks79]

Hey Rocker,

Thanks for the advice, i have actually gotten some brown packing tape to try on the next glue up. It sounds far easier than anything else!

Your advice, if i need to steam the 1.5mm lams then it isn't going to work? - im not sure how thinner i could go... ill try get them to 1mm or under and see how i go. What is the downside of steaming lightly, the lams, to complete the bend? also, you suggest i might get the bend after coating in glue... i know this is a hard one to answer, but is the additional bend or flex you get once glues substantial? - ill give it a go either way.

I've also ordered a few glues to try out, one of them being Techniglue epoxy - hopefully arrives during the week so next weekend i can try it out!

Ill keep you posted!

thanks again
T

[Manuka Jock]

T , how about trying the bend with solid timber

[ecks79]

T , how about trying the bend with solid timber

MJ - funny enough, i haven't. It all started because lams where supposed to give me minimal spring back, and for consistency (2 individual legs) it was the best option.

I also decided not to go steam bent solid wood because i wasn't equipped for it. strangely enough, i think i've spent more time and money going the lam route, that i could have become 'equipped' for steam bending twice over.

is there good math i could use to understand the spring back in solid bent - so the legs are parallel? trial and error?

T

[Rocker]

Hey Rocker,

What is the downside of steaming lightly, the lams, to complete the bend? also, you suggest i might get the bend after coating in glue... i know this is a hard one to answer, but is the additional bend or flex you get once glues substantial? T

Ecks,

The downside of steaming with epoxy is that water is not compatible with the glue. I can't really quantify how much extra bending you will get when the glue is on , but I think a minor amount of splintering will not matter too much, so long as it doesn't affect all the laminations. Possibly, if steaming is essential to achieve the bend, it might be better to go with a poly glue, which is compatible with moisture; but I have never used poly glue for bent laminations myself, and I am not sure if its working time would be adequate.

Rocker

[Manuka Jock]

MJ

is there good math i could use to understand the spring back in solid bent - so the legs are parallel? trial and error?

T
Not that I know of . have a look around the net .
The timber used will probably be a factor

[ecks79]

Thanks Rocker.

I don't actually glue up while the wood is still damp, i steam to get the bend once, then leave the clamped lams till they dry... steaming and bending once gives it enough flex that i can come back a week later and bend the lams a second time without stressing or splintering. So in this case, moisture shouldn't be a problem?

I was more concerned that, since i require so much steam and force to get the lams around the form... that the glue was not holding that shape over the week after the clamps had dried, and therefore flexing out of shape.

If the lams are dry, and having been bent once, allow me to bend again when ready for glue up - would this pose the problem i just mentioned?

[ecks79]

Not that I know of . have a look around the net .
The timber used will probably be a factor

Thanks MJ.

I have been looking all week, the general consensus seems to be "there is no definite way" and i've been advised that lams are really the only safe way when looking for conformity.

Ill find away :-)

Cheers
T

[mic-d]

I think once you get the lams bent and dried close to the correct bend you'll find that gluing them with the Techniglue will give very little springback. It's a very hard epoxy with virtually zero creep and for the bend to spring to any degree, the glue must creep.
You may also try overbending the lams and drying on a tighter form and hot pipe bending would certainly be worth investigating to do these lam bends. I have hot pipe bent 3mm lams to a 13mm radius so your radius is doable.

Cheers
Michael

[ecks79]

Hey thanks Michael... appreciate the feedback. Ill give that a go, sounds like it will be my best bet, as well the Techniglue sounds like a much better glue to work with :2tsup:

Cheers
T