Diy shims for gluing acrylic?

[Henry100]

Gluing acrylic without using shims,seems to be problematic.Thus,I decided to make a few shims out of polyethylene water containers or other thin strips of different materials.Using such shims I should be able to create a gap about 1mm deep and use the thick solvent for gluing acrylic.Anyone who has tried it before?Is it effective?

[Doahh]

Just go to home depot and pay a single dollar for some wood door shims...

[Henry100]

Thanks,for the answer!I searched on the internet and I found that the thinnest shims available are 1/16'' thick,which means they have the double thickness from my diy shims(strips out of water carrying container).

[GlassReef]

I'm curious, why would you want to use thick solvent when gluing acrylic? Or are you talking about something other than gluing two pieces of sheet stock together?

[chrismunn]

i think he's talking about using the pin method for acrylic welding, in which case you would want to use #4 thin solvent, not the thicker #16

a guitar string or a sewing needle would work fine. the wood shims are used underneath the project to help level it out and close any gaps in the weld joint...

[Henry100]

Just this!I want to use the thick solvent(which also works by capillary action) because I think it creates a full joint easilly,while the thin one seems to cover the full joint,but after a few hours it appears to have created only a half joint with many imperfections and gaps around it.

[chrismunn]

oh, huh?

well if your idea sounds like it will work then give it a try and let us know how it works out. :)

[GlassReef]

<a href=showthread.php?s=&postid=14164740#post14164740 target=_blank>Originally posted</a> by Henry100
... the thin one seems to cover the full joint,but after a few hours it appears to have created only a half joint with many imperfections and gaps around it. What you're describing is what often happens when one tries to glue a joint and does not apply pressure (normally in the form of weight) to hold the pieces together until the solvent dries sufficiently.

One other possibility for such a poor result is a solvent of insufficient quality.

[BeanAnimal]

<a href=showthread.php?s=&postid=14164280#post14164280 target=_blank>Originally posted</a> by Henry100
Gluing acrylic without using shims,seems to be problematic.Thus,I decided to make a few shims out of polyethylene water containers or other thin strips of different materials.Using such shims I should be able to create a gap about 1mm deep and use the thick solvent for gluing acrylic.Anyone who has tried it before?Is it effective?

Henry

Still trying to reinvent the wheel I see. Acrylic solvent is NOT glue, it does not fill gaps. You do not want a gap to fill.

The "pins" method creates a small gap to allow both surface to pull solvent in via capilarry action. The "pins" create a large enough gap to ensure that the proper amount of solvent can be pulled in. We use "pins" not "shims" to create the gap for a reason. The "pins" are narrow enough to allow solvent to flow around them and not cause dry spots or bubbles. "Shims" are simply not the proper tool for the job.

We use "shims" to slide between the workbench and acrylic to ensure that the flat panel is pressed tightly against the vertical panel. Wood or plastic "door" or "cabinet" shims are perfectly acceptable for this.

Trying to fashion DIY shims just does not make sense.

I will again kindly suggest that you master the "best practice" and/or time tested methods before setting out to invent new ones.

[BeanAnimal]

<a href=showthread.php?s=&postid=14164740#post14164740 target=_blank>Originally posted</a> by Henry100
Just this!I want to use the thick solvent(which also works by capillary action) because I think it creates a full joint easilly,while the thin one seems to cover the full joint,but after a few hours it appears to have created only a half joint with many imperfections and gaps around it.

The "thick" solvent will not work by capillary action and will not create as strong a joint. As mentioned in my previous post, "pins" should be used, not "shims". Furthermore, the "thick" solvent shrinks greatly as it dries. It is not at all suitable for the style of joint you are attempting to create.

[ReefEnabler]

... I once used some pieces of paper as the shims that go UNDER the acrylic, between the acrylic and workbench to snug up the pins, since I had run out of shims after using them to stir paint :D (ran out as in no longer had enough shims to put one under each pin). ya I could have just sanded off the paint buildup to get shims back but this was quicker...

just fold the paper enough times for desired thickness :D

but ya definitely don't use anything but Weldon #3 or #4 if you are doing the pins method, it just won't work. And you wouldn't want to use anything bit thin metal of some kind as the 'pins'. people have used anything from sewing needles to piano or guitar wire.

[ReefEnabler]

also, I found that when running the solvent, you actually get less bubbles if you let the solvent stay ahead of the applicator, as in do not get ahead of the puddle that is spreading in the space between panels.

Once I did that I got seams that were bubble free.


strangely I've read advice going both ways on that, but for me letting the solvent spread ahead of the applicator was much better.

[troylee]

henry,
the cheapest and easiest shim for you would be take a paper clip and smash it flat with a hammer........i personnaly use double ended razor blades that come with razor knifes........if you just insert the tip like a 1/16th lay your solvent and pull works like a champ.....also if you are concered with bubbles in the seam it is most likely your cuts....if you glue/weld a saw cut you will get problems you need to run a sanding block down the edge very carefully with like 180 grit and keep it flat it takes pateince......or weld a nice routed edge with like a triple flute bit to get the smoothest finish a machine can achieve if you are routing your pieces rough cut them with a jigsaw very close to the template size leave like a 1/6th to route off so you don't get alot of chatter and leave the edge rough........one other way to route is use a oversize bearing like a 5/8 bearing on a 1/2" flushcut bit run a pass around the piece then put the 1/2" bearing back on and route it flush then you will get a nice smooth edge to glue.....

[Henry100]

Thanks,guys for all the info you offered about this subject.I would like to add that I want to use strips of plastic or paper as shims for creating a gap between acrylic pieces and then apply weld-on 4(not weld-on 3 because that needs perfect edges and a perfect fit).My way is a bit different from the ''pins' method of gluing acrylic''.I will apply solvent along the joint except the points where there are shims.After 1 day,when the solvent has dried enough,I will remove the shims and I will apply solvent to these points,too.Isn't it a good idea?

[BeanAnimal]

My way is a bit different from the ''pins' method of gluing acrylic''.I will apply solvent along the joint except the points where there are shims.After 1 day,when the solvent has dried enough,I will remove the shims and I will apply solvent to these points,too.Isn't it a good idea?


No Henry, it is not a good idea at all.

Solvent welding is not gluing, it does not fill gaps. Weld-on #3 and #4 are NOT fillers, they are solvents. The solvent softens the two pieces to be joined. The pins allows space for the solvent to collect in sufficient volume to melt the edges before it all evaporates. When the "pins" are removed and the pieces pressed together, the melted surfaces intermingle and the solvent evaporates, leaving a single piece.

You proposed "method" will leave gaps that will not be easy to fill and will adversely effect the integrity of the seam. There is simply no advantage to doing it that way, and plenty of reasons NOT to.

Again, instead of trying to re-invent the wheel, you may want to stick to time tested methods and techniques. Your are new to woodworking and acrylic fabrication. I urge you to take the advice of those who have already mastered those skills. We keep going down this same path. You have to learn before you can invent my friend :)

[Henry100]

<a href=showthread.php?s=&postid=14179537#post14179537 target=_blank>Originally posted</a> by BeanAnimal
[b]


No Henry, it is not a good idea at all.

Solvent welding is not gluing, it does not fill gaps. Weld-on #3 and #4 are NOT fillers, they are solvents. The solvent softens the two pieces to be joined. The pins allows space for the solvent to collect in sufficient volume to melt the edges before it all evaporates. When the "pins" are removed and the pieces pressed together, the melted surfaces intermingle and the solvent evaporates, leaving a single piece. :)

If you talk only about weld-on#3,you may be right.But if you talk about weld-on#4,too,you are definitely wrong.Everyone who has used it,knows that it is quite thicker than weld-on#3 and its drops dry after a few minutes and result in a clogged syringe,which means you need a new one for further application of weld-on#4.I say this to show it gets a solid form through evaporation,it can't be gone.How this thing can disappear from the joint?I wonder...
:cool:

[Doahh]

WOW
Weld on 4 IS NOT thicker than weld on 3. You are WAY wrong and need to listen to Bean. It does evaporate and Never "Gets Solid" as you say. Pour a bunch of it into a steel cup and leave it for a while. It will not be there!

[BeanAnimal]

<a href=showthread.php?s=&postid=14179766#post14179766 target=_blank>Originally posted</a> by Henry100
If you talk only about weld-on#3,you may be right.But if you talk about weld-on#4,too,you are definitely wrong. No Henry, I am not wrong. Why is it that you tend to bite the hands of the people who try to help you? I see a distinct pattern forming my friend.

Everyone who has used it,knows that it is quite thicker than weld-on#3 and its drops dry after a few minutes and result in a clogged syringe,which means you need a new one for further application of weld-on#4. Henry, they are both "water thin" solvent cements. Neither is "glue" or designed to be a filler. They are NOT designed to fill gaps, period.

I have posted the product descriptions from the IPS website below. I have also posted links for the MSDS, where you cna find the ingredients and solids content. WO#4 is not "quite" thicker. WO#16 IS thicker. It is the same basic solvent with acrylic monomers dissolved in it. When it dries, it DOES leave acrylic behind, but still MOST of the volume is SOLVENT! I.E. it shrinks substantialy as it dries. It can be used to fill small voids and gaps, but does not produce a joint nearly as strong as a solvent weld. Notice it is listed as "cement", not "solvent cement" to denote the difference in usage?

3™: Water thin, non-flammable, very fast-setting solvent cement for bonding acrylic. It will also bond with other thermoplastics such as polystyrene, CAB (cellulose acetate butyrate), PETG (polyethylene terephthalate glycol) and polycarbonate to themselves. It will not bond to cross linked acrylics.
http://www.ipscorp.com/pdf/assembly/Assembly_3_MSDS_Jan08.pdf

4™: Water thin, somewhat flammable, moderately fast-setting, blush-resistant solvent cement for bonding acrylic. It will also bond with other thermoplastics such as polystyrene, CAB (cellulose acetate butyrate), and polycarbonate to themselves. It will not bond to cross-linked acrylic.
http://www.ipscorp.com/pdf/assembly/Assembly_4_MSDS_Apr08.pdf

16™: Medium bodied, fast-setting, high strength acrylic cement. Also bonds rigid PVC, ABS, styrene, butyrate, polycarbonate to themselves and each other, as well as other plastics and porous surfaces.
http://www.ipscorp.com/pdf/assembly/Assembly_16_MSDS_Apr08.pdf


I say this to show it gets a solid form through evaporation,it can't be gone.How this thing can disappear from the joint?I wonder...
:cool: Henry, take the lid off of your brand new can of WO#4 and leave it out for a few days. Let me know what is left after it evaporates.

Now try this, boil a pot of water dry and tell me what is left. Is water a good "filler" too? It did leave a crust on the bottom of the pan didn't it?

Solvents and glues are not the same my friend.

[Henry100]

Then,we surely talk about different solvents.I live in Europe and we don't have weld-ons,here.There are different products for the same purpose.So,I guess the solvent I have refered to,is weld-on#16.Let's talk about it and leave the other solvents alone.

[BeanAnimal]

<a href=showthread.php?s=&postid=14179933#post14179933 target=_blank>Originally posted</a> by Henry100
Then,we surely talk about different solvents.I live in Europe and we don't have weld-ons,here.There are different products for the same purpose.So,I guess the solvent I have refered to,is weld-on#16.Let's talk about it and leave the other solvents alone.

Weld-on #16 is not suited to capillary solvent welding Henry. It does not produce a joint nearly as strong as a true solvent weld. Again, the idea is to allow the solvent to soften both surfaces and allow them to intermingle and dry. "Solvent welding" and "gluing" are two differnt processes. Only one is acceptable for our purposes! If you want to "glue" the joint, then the ONLY acceptable way is to use a 2-part polymer resin like #40 or #42 or a 3-part product like #38.

Any way you cut it (no pun), your "shim" method is not going to work as well as the accepted methods of creating a joint.

[Henry100]

Henry, take the lid off of your brand new can of WO#4 and leave it out for a few days. Let me know what is left after it evaporates.

Now try this, boil a pot of water dry and tell me what is left.

Very good joke!:lmao:

[Henry100]

Bean,these are the solvents I use:
Altuglas SPC(thin solvent)
http://www.altuglas.com/literature/pdf/218.pdf
Adhesive S2002(thick solvent or,if you want it,thicker than the other)
http://www.altuglas.com/literature/pdf/216.pdf
While using shims,I can use only S2002,since SPC needs no gap in order to work.S2002 needs a gap to flow in the joint.

[ReefEnabler]

*edited my post since I think I misunderstood the intent slightly*


If your solvent that you are talking about IS indeed more like Weldon 16, or much thicker than WO4, here's why it won't work:

WO16 shrinks WAY down!! You may succesfully fill the gap between the acrylic if you make it sufficiently wide, but by doing so you will be insuring that as the stuff dries, it will shrink and peel away, leaving very very poor bonding with very little surface area. It is not the solid filler that you think it is!!

When it dries it will leave behind a pattern that looks like soap bubbles because most of the volume is in the SOLVENT, not the FILLER, as bean stated multiple times.


Yes I have used WO16 before, I tried lots of various things on scrap acrylic before I made my 5 acrylic tanks.

Even if you then go back over it and over it with multiple passes (like after you remove your shims), and eventually fill it up, it will be an incredibly weak joint that could be broken easily by human force.


Use the water thin stuff, and use the pins method as is. It's by far the best way for a DIY job.

[Henry100]

What I use IS a water thin stuff,since the above literature says it can be applied by capillary action.But it isn't the thinnest solvent and from my experience it needs a small gap between the edges so as to flow into the joint.If the edges touch with each other,then it can't flow into the joint.In this case,the first solvent must be used,as I mentioned above.From your disagreement I understand that you may have never used a solvent like S2002.

[calvin415]

Henry, sounds like you have made up your mind, so go build using this method and learn the hard way. Word of advice, don't do a test fill indoors. Good luck, you're gonna need it.

[BeanAnimal]

<a href=showthread.php?s=&postid=14181735#post14181735 target=_blank>Originally posted</a> by Henry100
What I use IS a water thin stuff,since the above literature says it can be applied by capillary action.But it isn't the thinnest solvent and from my experience it needs a small gap between the edges so as to flow into the joint.If the edges touch with each other,then it can't flow into the joint.In this case,the first solvent must be used,as I mentioned above.From your disagreement I understand that you may have never used a solvent like S2002.

Henry, you are not listening and have kind of talked yourself into circle.

So lets make this very clear:

The "pins method" is used to create a small gap. Without the small gap, the amount of solvent sucked into the joint is not sufficient to melt enough acrylic to make a strong joint. The gap needs to be narrow enough to still allow capillary action to wet both pieces and keep them wet. When the pins are removed, the two pices of acrylic (with their now mushy edges) are pushed together. The melted goo from each half mixes. The solvent evaporates and allows the acrylic to harden again forming a single "welded" piece of acrylic. It is NOT glue.

If the product you are using IS NOT water thin, then it is not the ideal product to use for a capillary solvent weld. It is GLUE, not solvent cement and will not produce a "welded" joint but instead a "glued" joint. If you want a "glued" joint, then you MUST use a stronger "glue" like the 2-part products made by IPS (and others).

I looked up the datasheet for your Altuglas S2002. It has a viscocity of 200 mPa.s. It is VERY THIN and MOSTLY solvent.

Nonetheless, in EITHER CASE your "shims" are not the ideal way of creating the "gap". We use "pins" becuase they are thin and allow the solvent (or glue) to flow aound them and make maximum contact. When they are removed, there is no dry spot left. Dry spots become small mountains that prevent the rest of the joint from mushing together. This creates a very inferior joint Henry. A flat "shim" shields a significant portion of the material from the solvent (or glue) and causes the "dry" spots. This is AT ALL an acceptable method or the proper way to build up a joint.

I am not sure why you find it so hard to accept the sound advice of others who have the knowledge and experience to teach you. It is starting to get kind of frustrating.

[noahm]

go ahead and do it your way henry. The shims will create too much gap to let the acrylic press together and you will get MORE bubbles from the gap AND your shims will be glued in place. But just try it so you can see for yourself.

I am very new to acrylic fab, but had no problems with the pin method after using the router to dress the edges. Also I found that a second pass on the table saw taking only a 1/32" off made a very nice edge as well (I did not buy a special blade since I was routing anyway).

Weld on 4 is just solvent, no filler.

[BeanAnimal]

That second to last sentence in my post should say "NOT AT ALL" instead of "AT ALL".

[troylee]

<a href=showthread.php?s=&postid=14182294#post14182294 target=_blank>Originally posted</a> by calvin415
Henry, sounds like you have made up your mind, so go build using this method and learn the hard way. Word of advice, don't do a test fill indoors. Good luck, you're gonna need it.
henry i second calvins posts i make my living doin this i have been running a plastic shop for 15yrs.......you are asking for disaster man take the advice me bean and a couple others have gave you they are all correct and have experince between all of us im guess in 25yrs or so why do you want to argue???if your mind is made up have fun dont listen to us and dont waiste your time or our's if you don't like the advice given....just please do one thing fill your tank outside and leave it there for a week or so.........and see what happens.....:eek2:

[NanoReefWanabe]

well since he is not really listening and going about things the opposite of what people are telling him it would be best to tell him to do a test fill in his house that way he might just actually go about it the opposite way as well and take it out side to explode...

after seeing most of Beans's creations and following Calvin's like an eagle i would not hesitate one single bit to do exactly what they say when it comes to fabricating with acrylic..

the wheel is round and has been so for a very long time...no sense making it octagonal again...

[stugray]

Henry100,


"What I use IS a water thin stuff,since the above literature says it can be applied by capillary action."

If you are using a "solvent" that is thin enough to apply by capillary action then it is 'by definition' A SOLVENT and NOT a FILLER as Bean has already explained.
It is impossible to have an adequate amount of filler ( for your method ) AND to be thin enough for capillary action.


When using the solvent, the shims must be removed before the SOLVENT evaporates or you will not get a good joint.

I have also used a lot of Weldon #3, #4, #16 & #40 and your approach will not work properly. It does not matter that you are using a different brand-name.

Stu

[savichus]

Sometimes I'm pretty stubborn tooooo... It's O.K. It's just cost more...

[Henry100]

Alright,guys.I have to agree with you and I won't do what I said.But I want to know if the ''pins method for gluing acrylic'' is necessary for a good joint or it can also be achieved by having the edges totally smooth using a router.

[stugray]

Henry100

"But I want to know if the ''pins method for gluing acrylic'' is necessary for a good joint "

You can use any method you like as long as you do the following:

place the two pieces that you want bonded, horizontally & with a small gap between them ( 1/32" approx. ).

Apply the solvent until the entire joint has been "wetted".

Wait X amount of time ( depending on solvent ).

Press joint together firmly.

Hold joint for X hours until solvent is allowed to fully evaporate.


You can use any way you like to maintain the gap as you apply the solvent as long as you can keep a consistent gap.



The pins method is tried & true, you just need to experiment before trying a big project.

Stu

[Henry100]

Yesterday,I tried my method with shims of 0,55mm thickness,using the S2002 solvent adhesive,which is thicker than SPC,but it also works by capillary action.It penetrated the joint until the half of it and it produced a clear joint where it flowed.So it seems obvious that shims of larger thickness are needed so as for it to penetrate all the joint.What are you saying about it?

[stugray]

Are you saying 0.55 mm ( ~ 1/2 of a millimeter )?

If that is the case we have all been arguing the same point.

When one speaks of "shims" we imagine something much thicker.
0.5 mm is about as thick as we are talking about with the guitar strings or "smashed paper clips".

And again, your original idea was to leave the shims in place until the solvent dries.

In my experince, you do NOT want to leave the "shims" in place until it dries.

Stu

[Henry100]

I left them in place until solvent has dried and today I removed them.It was quite an easy task and now I can apply solvent to these areas,too!When I first apply solvent,I care not to apply it where the shims are,but near them.

[Henry100]

The shims I used are out of paperboard and 0,55mm in thickness.The next time I will use shims which are 0,85 or 1mm in thickness,which I have already created.My way of solvent welding acrylic works only with a solvent adhesive like S2002,which is not the thinnest solvent,but it also has some fluidity and works by capillary action,too.The thinnest solvent adhesive can't be used in my way of solvent welding acrylic.This information is vital for everyone who wants to use this way of welding acrylic.

[BeanAnimal]

Henry, you clearly have refused to listen to the well informed advice given by others.

I don't know of any other kind way to tell you that your method is wrong. It could not be any more wrong. You are attempting to use a solvent to fill a gap like it was caulking. This is contrary to the Altuglas instructions and basic facts regarding solvent cements.

Again, the to create a proper SOLVENT WELD, the two pieces needs to be allowed to soften and then be firmly pressed together so that the softened (melted) portions intermingle with each other. The solvent evaporates and the two pieces are in essence one.

S2002
http://www.altuglas.com/literature/pdf/216.pdf
(BTW, they mention the use of "petroleum" to clean the acrylic... big no, no!).

I am not sure why you refuse to accept the facts here my friend. You act is if we simply don't understand the product you are using. Nothing could be further from the truth.

Henry, I have followed many of your threads and helped you in most of them. Oddly, for being so brazen in your sometimes outlandish claims, you are a very likeable guy. But, from my perspective (and surely that of others) you are trying way too hard to gain notoriety for inventing stuff and pointing out what is "best". I honestly thought you gained some perspective after the "jig" thread.

Think about this: In most cases, invention is the direct result of the inventor clearly understanding the shortcomings of a process, tool or method AFTER intimately mastering the process, tool or method and understanding its shortcomings. You are starting at the wrong end, trying to invent a better mousetrap without knowing anything about mice, mousetraps or bait.

[troylee]

henry what you have done is joined two pieces of acrylic by gluing them which is fine and it might very well look good to BUT! by leaving the spacers in you didnt allow the material to touch which in perspective didnt join/weld which means your joint is very weak......it will work for a cool little display but never in a million years hold pressure for a long amount of time.....try this since i know you got some scraps use a thin solvent with the pin method and weld 2 pieces at a 90 deg angle now use you method with the thick glue on a seperate sample let them sit for a few days once cured lay them on a table like a tent were the weld/glue joint is on top and hit them with a hammer if you welded correctly with the solvent it will break the acrylic around the weld now try it with your thicker gap filled sample i gaurentee it will bust the glue joint this is the simpliest way to do a demonstration for yourself and see.......

[NanoReefWanabe]

<a href=showthread.php?s=&postid=14193832#post14193832 target=_blank>Originally posted</a> by Henry100
The shims I used are out of paperboard and 0,55mm in thickness.The next time I will use shims which are 0,85 or 1mm in thickness,which I have already created.My way of solvent welding acrylic works only with a solvent adhesive like S2002,which is not the thinnest solvent,but it also has some fluidity and works by capillary action,too.The thinnest solvent adhesive can't be used in my way of solvent welding acrylic.This information is vital for everyone who wants to use this way of welding acrylic.

i am quite sure nobody wants to "weld" pieces of a tank together using "filler"....that is like "welding" on a new quarter panel to your car with a good ol' wad of bondo, pointless and bound to fail...

by leaving in the shims there is no possible way the pieces you "welded" have touched one and other and fused together to create a proper and solid piece, what you have done is created a halfa**ed joint between two pieces of acrylic, rather then a fused and solid piece of acrylic from two pieces...the difference being you still have two pieces of acrylic instead of one...and if you build a tank this way you will have 5 pieces of arcylic instead of one...properly welded acrylic fuses the pieces together creating a homogeneous piece, the five piece of the tank are one...your way is going to give you a tank consisting of five pieces....it will be interesting to see how well your joint holds up to being finish machined, dont tell us, you have invented a way to bypass this step too?