Thick or thin laminates when laminating a stem?

[tapsnap]

Is there a general consensus about the thickness of the laminates when laminating a stem? It is a part of the boat that is both in and out of the water so there is going to be unequal swelling of the wood. Is it better to have more glue joints or less? Would steam bending fewer but thicker piece together make for a stem that is less likely to come apart or more likely? For example, say I wanted to make a 6" thick stem out of black locust. Would it be best to make it out of 24 pieces @ 1/4 or 6 pieces @1"?

[paladin]

It depends on the wood and the thickness of the stem etc...the bendier the wood the less laminations, but the more laminations the stronger the stem and the less springback...in your case 24 pieces of whatever....and try to make the number of laminations come out odd.

[peter radclyffe]

3 laminations is stronger than 200,

200 which will be mostly glue, which has little strength of grain

[Canoeyawl]

If the laminated part is curved and will be bent on a form, the thickness should not be so great that it squezes out the glue.
Glue starvation is a common problem when gluing up curved pieces.
For a critical area I have made a test piece on the form and cut it open to measure the glue line thickness.

[Bob Smalser]

1) Is there a general consensus about the thickness of the laminates when laminating a stem?

2) It is a part of the boat that is both in and out of the water so there is going to be unequal swelling of the wood.

3) Is it better to have more glue joints or less?

4) Would steam bending fewer but thicker piece together make for a stem that is less likely to come apart or more likely?

5) For example, say I wanted to make a 6" thick stem out of black locust. Would it be best to make it out of 24 pieces @ 1/4 or 6 pieces @1"?



1) Assuming we're talking about a small boat, 1/8" is typical. That's the thinnest many planers will go without using a false table.

2) Not really. Stems are relatively small in cross-grain width and their movement is miniscule.

3) More.

4) More likely.

5) Neither. In general, always laminate using odd numbers of lams to avoid putting a glue joint at the point of most stress. Given a heavy bend, 33 laminations 3/16th-thick is closer to the mark....or 25 laminations of 1/4" for a lesser curve. Yawl's comment about glue starvation applies.

[wizbang 13]

Whaddya mean the bottom will swell more than the top? If you are gonna laminate it, it should be kept dry,NO swelling.
A 6" thick stem is sounding kind of "not small boat" Are you sure triple sawn and glued might not be better?

[tapsnap]

If the laminated part is curved and will be bent on a form, the thickness should not be so great that it squezes out the glue.
Glue starvation is a common problem when gluing up curved pieces. Indeed, I was thinking that the pieces would be steam bent first and allowed to dry sufficiently before gluing. That way, there is almost no pressure in the curve when the pieces are lightly clamped for gluing. However, it takes just one of those 1/4" laminates to be glue starved to create a significant weakness. However the more wood that is between each lamination, the more swelling, which creates stress on the glue. Hence my question.]

[lsimonson]

Hi Bob, Above, you write "always laminate using odd numbers of lams to avoid putting a glue joint at the point of most stress" I don't get it, would you please elaborate. Thanks.

[davebrown]

Divide 33 by 1/2. Dead center rests on wood, not on a glue line. But that is a guess. If I am wrong I am going to delete this and write something really clever instead.

[ssor]

And this is why plywood always has an odd number of plies?

[Mrleft8]

Plywood has an odd number of plys because the laminations are cross oriented. In order for both faces to have grain running the same direction, you need odd an number of lams.

[Bob Smalser]

Hi Bob, Above, you write "always laminate using odd numbers of lams to avoid putting a glue joint at the point of most stress" I don't get it, would you please elaborate. Thanks.

Picture thicker, 4/4 lams....say two of them assembled with flipped or alternated ring cups as in the photo of failing gluelines on the oak mast step lamination below. Ring cups are generally alternated in laminations and layups so that any tendency to cup or warp in one direction is opposed by the adjacent lam or panel board warping in the opposite direction. Any movement equals itself out and the overall assembly remains stable.

But when the humidity changes, wood in the assembly doesn't shrink or swell uniformly, but from the outside-in, often meeting in the middle, usually the point of greatest stress from seasonal movement. And where you want solid wood and not a glueline.

http://pic20.picturetrail.com/VOL12/1104763/7738131/388824026.jpg

[tapsnap]

Hmm, yes I see your point, but Bob, the interior of a stem is always relatively dry, whereas the outer radius is always wet. It would be difficult to predict the point of greatest stress.

[Bob Smalser]

... but Bob, the interior of a stem is always relatively dry...

Not really. When the wood eventually reaches equilibrium with the humidity in the air, it is the same moisture content in the center as on the surface. Wetting and drying on the outside surface has little to do with it, and when ambient humidity swings downward the wood is wetter on the inside than on the surface.

But using an odd number of lams is merely a rule of thumb, one that also has cosmetic benefits as Doug points out. The assembly won't fall apart if you don't do it that way.

[gibetheridge]

We're getting very technical here, and I'm just theorizing, but it seems to me that if I were building a 2" x 4" stem, or any size, for that matter, curved or not, I would want to consider having the "cups" all oriented in the same direction, thereby reducing the stress if wetting/drying were an issue, which it would not be since I would seal it very well. Also, and if it were available, I would use vertical grained laminations, cut thin enough that they would bend sufficiently without fracturing without steaming, the idea being that there would be no cupping.

Another point...When using epoxy resin to glue laminations, glue stavation can be avoided by not laying up so many laminations simultaneously that one must clamp so aggresively as to squeeze out all of the glue, and/or, laying a layer of 2 OZ glass tape between the layers, since it will maintain enough space that there will always be sufficient glue to create an excellent bond.

The trouble with the glass is that it dulls tools so quickly. It will also, however, pretty much eliminate any possibility of splitting.

[tapsnap]

Here is what prompted me to post this question in the first place. My plan was to continue building up the thickness one inch at a time, steaming the pieces over the top of the previous one. Eventually, after some drying, they would all be glued together.


http://www.danieloates.com/bentwood/laminatedstem1.jpg

http://www.danieloates.com/bentwood/laminatedstem2.jpg

[KM Bever]

I did mine just like you did, except 5/8 thickness and I clamped the wood at one end placed spacers every foot, and steamed them all at once. Then removed spacers and clamped all them into my jig. Came back in three days (work took me out of town). undid it glued (not much spring back) and clamped all of them back in jig. I managed to glue stem to base of jig, so use wax paper between (much less work).

KM Bever

[Peacefuljourney]

From my point of view, steaming is bad before gluing. You need dry wood to have the glue doing a good job.
If you steam it, it mean the wood is saturated with humidity before you glue, except if you put back the wood into the oven or wait a damn long time.

I used 1/4 pieces for my stem knee:
http://www.peacefuljourney.ca/stemknee.JPG

[CundysHarbor]

I recently made the forefoot for my White 23. It is ten feet long, ten inches wide and consists of 32 laminations, each 1/8 inch fir. A couple of observations....there was no springback, you need lots of help and lots of clamps and a strong form. There is lots of waste; I got six lams out of 2 inch (actual) stock. The design dictates this construction since the boat is to be very light for the sake of performance.

Dave

[Bill Mercer]

Another thing to think about. . . what are you using as glue? You said Black Locust, which as far as I know doesn't take epoxy well (I've heard that epoxy doesn't soak in enough to give a really reliable glue joint), so you might want to go with some kind of resourcinal. Also with resorcinal, the thickness of the individual glue lines had better be negligible to nonexistent, so Peter Radclyff's worry about more glue than wood won't be a problem. Also of course, the more glue lines the less stress on each individual glue line from shrinking/swelling.

I'd be interested to hear from folks with actual experience gluing locust.

[peter radclyffe]

break a 2mm piece of wood in your hand
bend a piece of 20 mm wood in your hand

[Peacefuljourney]

Another thing to think about. . . what are you using as glue? You said Black Locust, which as far as I know doesn't take epoxy well (I've heard that epoxy doesn't soak in enough to give a really reliable glue joint), so you might want to go with some kind of resourcinal. Also with resorcinal, the thickness of the individual glue lines had better be negligible to nonexistent, so Peter Radclyff's worry about more glue than wood won't be a problem. Also of course, the more glue lines the less stress on each individual glue line from shrinking/swelling.

I'd be interested to hear from folks with actual experience gluing locust.

True, but also resorcinol & Epoxy need a minimum of 15% MC, which you are way over with steam bending the pieces.

[Peacefuljourney]

break a 2mm piece of wood in your hand
bend a piece of 20 mm wood in your hand

It's not about a single piece in your hand, it's about different grain orientation that give the strenght to it.
Bend a 1/4" marine plywood with the most thin layer, bend a 1/4" wood... You will see the difference.

[Bob Smalser]

C'mon guys. Don't go claiming numbers about how wet freshly steam-bent wood is unless you measure it with a moisture meter and know for sure.

Thin lams only need a few moments of steam, and if you keep them high and dry above the condensate at the bottom, you'll find you can steambend them and then epoxy them together as quickly as they cool off. If 5-10 minutes of dry steam followed by 30 minutes of cooling raises the MC by more than a point....I'll buy you lunch.

Steambent Douglas Fir knees....a genuinely stiff wood in 8th-inch lams....glued in place using epoxy that calls for a 12% upper limit for moisture content. Haven't had a failure yet. And I've done dozens of them.

http://pic20.picturetrail.com/VOL12/1104763/8408305/113221960.jpg

http://pic20.picturetrail.com/VOL12/1104763/21637099/392573227.jpg

http://pic20.picturetrail.com/VOL12/1104763/8408305/382803882.jpg

http://pic20.picturetrail.com/VOL12/1104763/21637099/359943593.jpg

http://pic20.picturetrail.com/VOL12/1104763/21637099/392573229.jpg

And if you still have qualms about epoxy....or if you boil your lams in water instead....simply heat them and use liquid poly glue...which has a higher upper limit for moisture content....after they dry. And unlike epoxy, poly's open time isn't affected by heat. All the current buzz (based on a FWW article) that polys are weak glues is nonsense on stilts. Glue only has to be stronger than the shear strength of the wood....and all woodworking glues are.

http://pic20.picturetrail.com/VOL12/1104763/21637099/383860255.jpg

On Tapsnap's 4/4 oak lams that spent an hour or so in the box however, I'd definitely take MC readings before spreading resorcinol. But I suspect if the starting point was air-dried oak at 12% MC, and hour of dry steam followed by cooling and setting in the form would still fall well within the 15% upper limit for resorcinol.

[Bill Mercer]

break a 2mm piece of wood in your hand
bend a piece of 20 mm wood in your hand

But if you have a large number of say 3mm pieces laminated together with a minimal glue line, say with resoricinal, won't that have the same strength as a natural piece? Assuming of course that all of your laminae don't have crazy grain runnout or some such.

[Bob Smalser]

But if you have a large number of say 3mm pieces laminated together with a minimal glue line, say with resorcinol, won't that have the same strength as a natural piece? Assuming of course that all of your laminae don't have crazy grain runnout or some such.

There are diminishing returns at both ends of the spectrum of lam thickness. You have to understand your materials.

While oak, ash and walnut will take a tight-radius bend, Doug Fir, pine and spruce won't and the lams have to be thinner. In turn, the hardwoods move a greater amount seasonally and the thicker the lams, the greater the risk of seasonal movement or cupping breaking a glue joint.

In general, laminations are stronger than solid wood, but milling lams thinner than required to make the bend can weaken a structural assembly by the end result having more homogeneous plastic in it than unidirectional wood. Like concrete without rebar....weak and brittle.

[tapsnap]

In my experience, steamed wood drys relatively quickly to a point where it can be glued. The wood I use for bending is always green, but the steam seems to replace the sap and then moisture comes down fairly quickly; in a matter of a couple of days.

I can see how, as Bob Smalser says, there are diminishing returns at both ends of the spectrum in lamination thickness.

[Peacefuljourney]

Well.... Ok let's take a example.

Open your TV, and watch a hockey game. Those stick are made with 1/32" thick lamination of wood.
Tell me they are not having a hard life during a game, and try to do it with a thicker piece of wood, they won't last long.

1 1/2" thick pieces of 1/32" lamination can hold all the weight of a hockey player + the gear, and still hit the ice with it without even breaking.
Now you won't make me believe lamination is not strong even when really damn thin.

Even get one here, professionally build hockey stick. It's a 3/8" in the middle and cover both side with 1/64" thick lamination. Can't break it even if I am jumping on it full weight...

[peter radclyffe]

you make a 1 ton mast of 1/32" laminates, how much of it is glue, how brittle is it

[Vinny&Shawn]

How large is the craft you are building?
Is there a reason for steam bending the stem and not using traditional building methods of scarfing the stem, forefoot and keel?
That is using solid pieces chosen for the task!

[Peacefuljourney]

They build wind generator blade at 2 corners from where I live.

They are all more then 200 foot to 400 foot long. They use the smallest lamination they can.
They use 1/16" thick venner of BC Fir.

I think this is longer and get more pressure then a mast.
Gudgeon brothers have made several of the same blade to show that is was the strongest for cheapest material to build those.

[Peacefuljourney]

Ok found the document of the gudgeons brothers:
http://www.google.ca/url?sa=t&source=web&cd=7&ved=0CEEQFjAG&url=http%3A%2F%2Fntrs.nasa.gov%2Farchive%2Fnasa%2F casi.ntrs.nasa.gov%2F19830019076_1983019076.pdf&rct=j&q=windgenerator%20thickness%20of%20wood%20laminate d%20blade&ei=yazRTIWPHsOBlAed0fSkDA&usg=AFQjCNG3waT5W9JLPXlM2hu0VH0liFv1Eg&sig2=8VcIXSOapb1jdj_VIXwIIQ&cad=rja

Check paragraph 5.1, This was for 2x 60ft wind generator blade.

[peter radclyffe]

this is very interesting, but if it was that good why dont they make 80 ft masts to take a gybe full standing without standing rigging

[Peacefuljourney]

I guess there is a weight ratio. 80 ft mast full standing without standing rigging this will only be for a racing boat, not a cruising one.
For a racing boat you want the most lightweight mast as it high in the air, so for that carbon fiber is better...

[peter radclyffe]

i dont believe a 200 ft blade has the same stress loading as a tall ship mast, a blades isolation is a great plus in its survival

[Peacefuljourney]

Maybe not, but it'S blowing damn hard here during the winter.
A storm at -40 celcius with 60 knots wind it's not rare in february and you still see those wind generator turning at the top of the hill not far from here.

At that cold temperature this is quite some test....

And this prove the first arguement that thinner the lamination doesn't mean at all that it will weaken the structure it's actually show the opposite.

[Vinny&Shawn]

I think Peter is right, the aerodynamic lift of a blade or wing, distributes the stress load, in such a way that the blade or wing is supported by a cushion of air.

[Peacefuljourney]

Aerodynamic work if it's a engine turning the blade which is not in that case and the opposite.

A 200ft blade turning at low speed in 10knots breaze, and sometime dead at 90 degres holding only by one side probably don't have any pressure on it right.?
200 ft long stick straight horizontal it's nothing, probably less hard to hold then a vertical mast... right?

[Peacefuljourney]

I am not debating which one is the worst between mast and wing.

I am debating on the fact that tinner lamination it's NOT weaken a structure. It's stronger in much case, as the hockey stick or the wind generator blade.

[peter radclyffe]

http://en.wikipedia.org/wiki/Ice_hockey_stick

are these blades & sticks reinforced with other materials, like g r p

[Songololo]

On this Wee Rob canoe build, both the inner and outer stems were laminated from unsteamed 1/8'' DF laminates at approx. 12'' radius of curvature without any problems. Each stack of laminates was however gradually pre-bent by clamping to the laminating form over a few days prior to glueup. West System epoxy and fillers were used. Here, stems (both inner and outer together) are approx. molded 2.25'' and sided 7/8'':

http://farm3.static.flickr.com/2738/4511864230_86813996e2.jpg

[Peacefuljourney]

http://en.wikipedia.org/wiki/Ice_hockey_stick

are these blades & sticks reinforced with other materials, like g r p

I got around 10 hockey stick here only laminated wood which are used by players paid millions dollars a year, which can'T have a stick break in a middle of a game,

I gived you a document writed by the NASA & Gougeons brothers for the U.S. DEPARTMENT OF ENERGY that thin lamination can be used to build huge wind generator blade that withstand lot's of pressure.

If you still want to believe yourself because it's your belief. Well good for you, but I do prefer facts.

[tapsnap]

Peacefuljourney, the hockey stick has glass fiber bonded to the wood with epoxy. As do other of your examples. I thought we were talking strictly lamination thickness. Throwing in glass fiber and carbon fiber, as you have done in your argument, is another conversation.

[Peacefuljourney]

AAA men I will have to take pictures I guess.
Ok on the document:
" trimmed veneers are temporarily bondededge-to-edge by using a zig zag pattern "stitching"
machine that lays resin preimpregnated fiberglass roving in
along both edges of adjoining veneers"


Look the figure 8 at the end... So you are telling me the small fiberglass wire that they use to stich those venner side by side with a zigzag machine is what holding everything down...

And I guess in a big 80 ft cold molded hull which is not cover with fiberglass is also solid because of the plastic stample holding those veneer together?

[Peacefuljourney]

Think about it a second.

Why they build huge racing boat with 1/16" venner, several layers going different directions.
Why does they just steam bent 1/2" pieces, hold it there and glue. Will be way faster, cheaper and by your way of thinking stronger.

I guess the whole industry is wrong then!

[Peacefuljourney]

Ok just remember another article about this too, one from Paul gartside again'ts strip planking and prefer cold molding because tinner venner is stronger and stiffer:
http://www.gartsideboats.com/faq2.php#strip

He also suggest to don't use sheating on the hull,

Don't tell me this naval architect is also wrong?

[chuckt]

I did a hair under 1/4 inch for this lamination using Douglas Fir. I don't think that thickness would have taken a more severe curve without cracking (assuming you don't steam). I thought about steaming but was worried about the moisture and glueing and did not want to wait for the wood to dry back out before gluing. If you are doing a smaller radius you may have to steam. I think the Gougeon tech guys told me that an inch or less they dont worry about the thickness affecting the longevity of the lamination. This assuming you are laminating with wood suited to the task. Good luck!
http://i571.photobucket.com/albums/ss151/cmeke0870/work%20begins/IMG00112-20100413-1647.jpg

[peter radclyffe]

Think about it a second.

Why they build huge racing boat with 1/16" venner, several layers going different directions.
Why does they just steam bent 1/2" pieces, hold it there and glue. Will be way faster, cheaper and by your way of thinking stronger.

I guess the whole industry is wrong then!
they use thin lams because they are easier to shape & hold in place, & to cover all seams & the hull is strong enough with thin lams, if they used i layer of half inch they would not be able to seal the seams properly, & it would be hard to fair the hull, the multilams fair themselves in

[Peacefuljourney]

they use thin lams because they are easier to shape & hold in place, & to cover all seams & the hull is strong enough with thin lams, if they used i layer of half inch they would not be able to seal the seams properly, & it would be hard to fair the hull, the multilams fair themselves in

Ok a serious study between solid stock and laminated, which test both, with different way of laminated came to the conclusion:
The modulus of rupture averages slightly higher for the laminated beams
with straight grain then for solid beams, but the difference is not con-
sidered significant. The modulus of elasticity is appreciably higher for
laminated then for solid beams, and it seems likely that the glue has added some what to the stiffness . The laminated beams are also slightly higher in maximum crushing strength parallel to the grain. In work values the laminated beams are considerably lower. This apparent deficiency is not, however, substantiated by results of the impact bending tests in which laminated end solid beams have the same average values. Furthermore, in toughness, another measure of shock resistance, the laminated and solid materials had practically the same average values when the load was applied on the radial surface; when the load was applied on the tangential surface, the laminated beams averaged
considerably higher in toughness than the solid. Considering all the values
measuring shock resistance, it appears that laminated stock is not deficient in this property as compared to solid.

The whole conclusion of all the test, solid & Laminated part have pretty much the same value in strenght. Some laminated are better specially when lot's of curves.

http://www.google.ca/url?sa=t&source=web&cd=5&ved=0CDUQFjAE&url=http%3A%2F%2Fwww.fpl.fs.fed.us%2Fdocumnts%2Ffp lmisc%2Frpt1512.pdf&rct=j&q=thickness%20wood%20laminate%20airplane%20wing&ei=i-jSTPfoEsH6lwebgt3YDQ&usg=AFQjCNFH5eE1soHUkN0ZMcrVk_bAhyexGg&cad=rja

I am done here, That's the perfect study between laminated & solid. You can complain about the wood or the glue now, but I have showed my point and you can tell me again that I will never understand, but personnally I think pretty much the opposite.

[cap'nRod]

Neither is 'better'. Too many variables. The 'better' thing to do is to find a stump and cut your stem out of 1 solid piece.

[Reynard38]

I used @ 3/32" laminates of cypress and had NO springback at all. Using west epoxy and silica filler no voids at all. I think I used @ 30 strips total for the inner and outer stems of a Coquina.

[Wacoflyr]

Wow. Amazing how these threads go. On another note, if you are going to use epoxy, I recommend first coating with thin epoxy, letting that soak in briefly, and then coating with thickened epoxy just before you put each piece in the stack. The thin epoxy soaks into the wood, and chemically binds with the thickened epoxy, which is less prone to squeeze out. If you do this right, you are far less likely to have a starved joint. Worked a treat on my pooduck. Goodluck!

Wacoflyr

[kenjamin]

Peaceful Journey,

They did not use epoxy glue in that test. You may find epoxy works much better than that glue they were using forty years ago or from whenever that test was conducted. Your results may vary.

[Peacefuljourney]

Peaceful Journey,

They did not use epoxy glue in that test. You may find epoxy works much better than that glue they were using forty years ago or from whenever that test was conducted. Your results may vary.

So what do you say is: If a test with a much less worth adhesive then Epoxy, it proved that a lamination is stronger. So If I understand, you are saying that lamination would be way stronger then solid wood with a better adhesive like Epoxy?

[esingleman]

You can easily use thicker laminates. I used six 1/2 inch laminates for the stem of my 12 1/2 to reduce the amount of gluing and the associated mess. I pre-steam bent the laminations to the form to get them close to the final shape, and then clamped them glued to the form for the final glue up. What you have to realize with the thicker laminations is that there will be a tendency to have gaps if you do not have enough of or heavy enough clamps (the pre steaming helps a lot here but does not necessarily eliminate this problem). Therefore I elected to use West System G-Flex epoxy for its gap filling qualities. G-Flex is formulated to work with difficult to bond woods such as white oak which my stem is made of. I won't know the actual results of my work for many years to come, but I trust the people at West System that this glue will be appropriate for this application. BTW, there was absolutely no spring back of the stem from the form when the clamps were released.


http://im1.shutterfly.com/media/47a0d735b3127ccefb481b173b3a00000030O00AaMm7Jm0ct2 QPbz4E/cC/f%3D0/ps%3D50/r%3D0/rx%3D720/ry%3D480/http://im1.shutterfly.com/media/47a0d735b3127ccefb4842c17b5800000030O00AaMm7Jm0ct2 QPbz4E/cC/f%3D0/ps%3D50/r%3D0/rx%3D720/ry%3D480/



file:///C:/Users/Erick/AppData/Local/Temp/msohtml1/01/clip_image001.gif

[tapsnap]

Peacefuljourney, look at the first post. There is no mention of strength in that question. You have been going on and on about laminate strength for most of this thread, going to great length to prove your point. Trouble is you are missing the point. Strength in this situation is not really an issue. I'm quite confident that either way it is built, the stem will not fail due to lack of strength. My concern had more to do with de-lamination; specifically the effect of swelling of wood in a thick 5 layer lamination versus the possibility of glue starved joints in say a 16 layer lamination.

[Peacefuljourney]

Peacefuljourney, look at the first post. There is no mention of strength in that question. You have been going on and on about laminate strength for most of this thread, going to great length to prove your point. Trouble is you are missing the point. Strength in this situation is not really an issue. I'm quite confident that either way it is built, the stem will not fail due to lack of strength. My concern had more to do with de-lamination; specifically the effect of swelling of wood in a thick 5 layer lamination versus the possibility of glue starved joints in say a 16 layer lamination.


Well sorry then, I am one of the believer that a stem need to be solid first. Most of the time you gonna hit something it's gonna be right at the bow, which is the stem taking up all that shock at first.

So if for you a stem is not a piece that need to be strong. Well then you are right either way is good, just take the one that your prefer.

[esingleman]

There are several advantages of laminations over a solid stem. If one of the laminations has a defect, the effects of that defect can be limited to that lamination alone. For example, rot or checking can be halted at the glue line. A single piece stem from a crotch is less likely to have the grain running exactly parallel to the curve of the stem, making it somewhat weaker. Single piece stems that are steamed require green wood; will the drying process cause the stem to twist or other wise change it's shape? Both solid and laminated are good, I just happen to think a laminated stem is better, provided the glue bond is good. I am putting my faith in the manufacturers claims for G-Flex, and in myself in that I have prepared the piece and applied the glue as per the instructions. We'll see in 25 years if I made the right decision, if I live that long.