LumberJocks

Sticking it Together; What Glue to Use?

  • Advertise with us

« back to Woodworking Skill Share forum

Forum topic by Mark A. DeCou posted 2805 days ago 15228 views 5 times favorited 18 replies Add to Favorites Watch
View Mark A. DeCou's profile

Mark A. DeCou

1973 posts in 3010 days


2805 days ago

Topic tags/keywords: glue ca pva what to use selecting repairs joints gluing picking mark decou decoustudio

==================================

2-21-2012 UPDATE:
This short Lumberjock’s Forum Topic article was updated and expanded suitable for printing in the “The Maine Journal of Antiques & Collectibles”.

For a reprint of the better, and expanded article, contact:

Bob Stover, Publisher
The Maine Journal of Antiques & Collectibles
71 Church Street
Belfast, ME 04915

===================================

Using the Right Glue in the Right Place.

I’m not a chemist, and I’m not a glue seller. However, I am a glue user, and there are several things that I have learned that others might benefit from, so I decided to post some comments about glues. The type of information that I have learned on my own, and through reading.

In cases where I have learned about new techniques and products through reading, I seem to only feel confident with the information after I have tried it myself, so I am only providing information here that comes from my own experiences.

As with any tool, Glue is something that I have to learn to use right, learning the tricks by experience. This experience shows me where my assumptions were wrong in the past, and allows me to make adjustments in my techniques. About 10 years ago, I only had one type of glue in my shop, and it was a bottle of Carpenter’s glue, which I have learned since is called PVA glue. Over the years, I have developed techniques that require me to keep on hand various types of glues for each application.

I use PVA wood glues (Polyvinyl acetates) for all wood joinery, except loose joints, which I discuss below. These PVA glues are the same type that all of us use, in brand names such as Elmer’s, and come in either white, or yellowish colors. There is a shelf life of around a year, so I buy smaller bottles as I need it throughout the year. I prefer Woodworx PVA glue that I buy at Wal-mart. The price on this product has gone up a lot in the last year, and so if it continues to climb, I might be searching for alternative brands, or retailers.

I like Woodworx because it sets quickly, and any spill out when clamping will dry quickly. If I leave the spill-out alone for about 30 minutes it will easily scrape off with a scraper or knife point. However, if I leave it longer, such as over night, this stuff is tough to scrape off, and will pull out wood fibers when it releases when scraped. Also, if I try to wipe Woodworx up with a rag, it will be pushed into the wood fibers, and it is hard to get out so that the following wood stain process will darken the wood consistently.

On unstained wood, the dried spill-out glue will prevent the wood from absorbing the wood finish consistently, and a whitesh spot appears in the first coat of whatever finish I am applying. Normally, I find these white spots in my finish where I had a spot of glue on a finger when I touched the unfinished wood somewhere during the clamping process. When I find these small white spots in the finish, I scrape them out with the side of an Exacto Blade, and apply more finish, easily and quickly removing the dried glue spot, without sanding. I learned the hard way about 9 years ago to not spot sand a glue spot, as the spot leaves sanded fibers that are different than the adjacent wood, and the wood subsequent staining process will only highlight the flaw. Scraping with the small Exacto blade works great. When a blade is dull or gets too covered with dried glue to work well, I toss it, and get another out of the pack of new blades.

I prefer to never clean up PVA glue with a wet rag. Water thins the glue, and so I don’t want to introduce moisture that might weaken the glue, and also I don’t like to sand a project again. I use PVA glue on joinery after all of the boards have been final sanded to 220 Grit, and so I don’t like to wipe around with a wet rag at that point. If I keep the glue squeeze-out to a minimum with careful glue application, then the resulting spill-out can be scraped up in about 30 minutes as described above.

Another key glue that I keep on hand is the family of CA Glues, one brand name for this chemical is “Super Glue.” There are many different brands, but all in the same family of “cyanoacrylates”, thus shortened to “CA.”

I keep four kinds of CA glue on hand. I use Thin for crack stoppage, Medium for sawdust/CA knot filling, Thick for gap filling, and Flexible for times when I think I want the glue to be somewhat rubbery when dried. With this assortment, I also keep on hand a “Debonder” and also a spray can of “Activator”. When I first learned to use this CA glue, I used the Debonder to unglue my fingers occasionally. Over time, I have learned how to use it, to where this rarely occurs anymore, but is always a risk. Once, I actually glued the thumb and forefinger of both hands together. That was a little embarrassing for my wife to help me with. I have also learned to not hold the bottle lid in my mouth while trying to put the cap on. I missed the lid once, and quickly glued the tip of the bottle to my lips, not a pretty isight.

After reading once (forgotten source) that CA glue was first developed for first aid officers to stop bleeding of wounds during the Viet Nam war, I started to hold my fresh cuts closed and drop a small dot of CA glue over the cut. What happens is that the bleeding stops quickly, and the cut is sealed, not requiring a bandaid. It stings a little, but not bad.

Now, I am not a doctor, so I take no responsibility of any kind for someone doing something with CA glue that could be remotely associated with a health risk. I am merely stating how I have effectively used it to stop a bleeding cut, happily keeping me working along in the shop, and avoiding the worried questions of my children and wife when I walk in the house with blood dripping, as in the old days. Since I started using CA glue for this injury repair purpose, I rarely have to let anyone know I was injured in anyway, as my cuts are usually small and from carving tools, and easily sealed with CA glue. I would not use CA glue on a Bandsawn finger (another story sometime).

I have searched many places to buy bigger quantities of CA glue, to reduce the cost. I have settled on 4oz bottles from www.hobbylinc.com, where my research shows has the best price, and provides an excellent product in the brand name Pro CA. They ship quickly, rarely taking more than 3-4 days for a UPS package to arrive at my remote location. Here is an item number of the Thin glue if you are wanting to search for it on their site: “gpmgpmr6004.” They have a lot of different brands, sizes, prices, etc., so it can be confusing seeing the entire list.

When I want to speed up the natural curing of CA glues, I prefer to let the glue cure for a few minutes before spraying it with Activator. I have learned that if I let it air-cure for a few minutes, it will cure clear, with no white-ish color after I hit it with the Activator. The thinner the CA glue I am using, the shorter amount of time I need to wait. For instance, when using the Thick glue, I might wait an hour, or even over night, but only a minute for the Thin. I learned the hard way that if I quickly hit a Thick CA glue with Activator without waiting for it to air-cure a while, the resulting cured glue may turn out white, or at least cloudy, which shows up bad on Walnut, my preferred wood. When that has happened, I air-brush some paint over the white-ish color.

Air-brushing has given me a lot of help with my projects this year, and at some point I will write out all of the useful ways it has helped, and why every woodworker should consider having an air-bursh kit in their shop.

Back to CA glue:
I never use CA glue for a “joint” glue. It doesn’t hold wood joints well. I have used it to put together little things like toys, but then I find that in a couple of years, the glue has debonded, and the part falls off. So, from that experience, I never use CA glue where PVA glue should be used on wood joinery. I have used PVA glue on a joint, and hit a couple of drops of CA also in the joint, so that I didn’t have to hold the joint with clamps. I held the joint in place by hand, and sprayed a little Activator on the joint, which sets the CA glue, holding the joint in place while the PVA glue continues to dry. That has worked well with small parts, especially those those that are impossible to clamp until the PVA glue cures.

Loose Joints:
For loose joints (bad joinery) I use 2-Part Epoxy glue, either in 2-minute, 5-minute, 15-minute, or 30-minute curing times, depending on the situation. If the joint is a critical joint, where a lot of stress will be applied during the use of the finished product, I will re-cut the joint. I don’t rely on Epoxy glue to hold critical stress areas.

I mix 2-Part Epoxy a little light on the activator, so that the final cured glue is not hard like plastic, but slightly pliable. This is why I prefer to not use the double syringe style epoxy packaging, as I can’t alter the amount of glue vs. activator easily.

I also buy epoxy from www.hobbylinc.com, as it seems to be the best price I can find in the size bottles I need for my typical projects. I don’t use a lot of it, so I don’t really want to have a gallon bottle getting old on my shelf.

I have also used Polyurethane glues for outdoor products, but choose to never use them on indoor products. One brand name I have used is “Gorrilla Glue. There is a misconception on woodworking self-help websites about using Poly glue on loose joints. I don’t recommend this, as the bottle label says to use the glue on tight joints. When Poly Glue cures, it does expand, but the expansion is a foam, not a hard material like Epoxy provides. I got some heat once from a couple of woodworkers on another website for suggesting they not use Poly glue on loose wood joints. So, don’t argue with me, just read the label.

Let me know what I missed, what questions you have, and what experiences you have that are different than mine, I will enjoy learning.

Mark DeCou www.decoustudio.com

-- Mark DeCou - American Contemporary Craft Artisan - www.decoustudio.com


18 replies so far

View Dick, & Barb Cain's profile

Dick, & Barb Cain

8693 posts in 2903 days


#1 posted 2805 days ago

I started using masking tape up close to the glue joints. That way any squeeze out ends up on the tape. In the past I’ve been plagued by glue spots while staining. This seems to remedy the situation.
Years ago thats all they had was Elmer’s white glue, & I haven’t had anything come apart on me using White glue.
I used to have a formula for making your own white glue using milk, but I have misplaced it over the years. Maybe it can be found on the internet.

-- -** You are never to old to set another goal or to dream a new dream ****************** Dick, & Barb Cain, Hibbing, MN. http://www.woodcarvingillustrated.com/gallery/member.php?uid=3627&protype=1

View Dick, & Barb Cain's profile

Dick, & Barb Cain

8693 posts in 2903 days


#2 posted 2805 days ago

Another Glue that I’ve used is Franklin liquid hide glue. It has a long open time.
It came in handy when I built some Windsor chairs, when I glued the back, & arm rest bent laminations where I needed that extra time.

-- -** You are never to old to set another goal or to dream a new dream ****************** Dick, & Barb Cain, Hibbing, MN. http://www.woodcarvingillustrated.com/gallery/member.php?uid=3627&protype=1

View scottb's profile

scottb

3647 posts in 2931 days


#3 posted 2805 days ago

on the use of CA glue in place of bandages…

I had an accident (kitchen, not shop) several years back, I nearly took off the tip of my thumb. The knife was sharp, and I never felt a thing. Anyhow, this was on a saturday afternoon, and I ended up waiting a few hours for the doctor to basically cover the tip of my finger with glue, and wrap it in gauze to keep it dry (and look like a much more impressive injury). If not for the tetanus booster, I could have done the same thing myself (which I did a few years later – same thumb – to no ill effect).

So, I managed to get out of cooking a “thank you dinner” for my parents, In-laws, and grandparents for all their help over the previous 6 months with our house. Fortunately, they didn’t seem to mind taking over in the kitchen (my domaign, not generally my wifes) cooking their own thank-you meal.

-- I am always doing what I cannot do yet, in order to learn how to do it. - Van Gogh -- http://blanchardcreative.etsy.com -- http://snbcreative.wordpress.com/

View dennis mitchell's profile

dennis mitchell

3994 posts in 2918 days


#4 posted 2805 days ago

Thanks for all the information on the CA glues.

View jockmike2's profile

jockmike2

10635 posts in 2851 days


#5 posted 2788 days ago

Mark, one you did’nt touch on. What kind of glue to use for veneer? I need to put a ribbon of veneer around my daughters lid edge. It does’nt say on the package what to use. Your help would be greatly appreciated. mike

-- (You just have to please the man in the Mirror) Mike from Michigan -

View Karson's profile

Karson

34862 posts in 3005 days


#6 posted 2787 days ago

Mike: I use a veneer glue that is probably a PVA glue in my vacuum veneer press. I’ve not used veneer on the edge of anything because of my concern for lifting of veneer that seems to occur when clothing products hit corners and other thin places. I’ve not tried but I read where you can put pva glue on both the substrate and on the veneer and let it dry and then iron on the edge, like the prepared edging that you can buy. Like I’ve said I’ve not tried it so I can’t speak from experience on this. I tend to use solid wood for edging. about 1/4” thick and put a bead on it and then make it proud of the surfice you are placing it on.

-- I've been blessed with a father who liked to tinker in wood, and a wife who lets me tinker in wood. Southern Delaware karson_morrison@bigfoot.com †

View thewoodwhisperer's profile

thewoodwhisperer

601 posts in 2788 days


#7 posted 2787 days ago

Hey guys. Just thought I’d throw in my 2 cents on veneer glue. I have done the PVA glue ironing trick and it actually does work. But you should definitely practice on scraps first. There’s a little bit of a learning curve. Honestly though, Im not a real big fan of pva glues for veneering applications. I use Unibond 800 for all of my veneering. Its a 2 part plastic resin glue that provides a very rigid glue line and doesn’t introduce water into the veneer. You also have a very long working time.

Now for edging, I never bother applying veneer strips unless they are pre-glued. Its just too much darn work for me any other way. :) And I have to agree with Karson about using home-sawn 1/4” thick edging whenever possible. But if I were applying edge tape that wasnt pre-glued, I would probably use regular pva glue and make a long caul with cork on the business end. This will help you get even pressure all along the joint.

Good luck!!

Marc

-- For free video tutorials and other cool woodworking stuff, check out http://www.TheWoodWhisperer.com

View jockmike2's profile

jockmike2

10635 posts in 2851 days


#8 posted 2785 days ago

Thanks guys, well I’ll flip a coin and iron and vacuum a 1/4” of edging and put a long caul on it all andand ….... just kidding. You were a lot of help. I bought enough stuff I should make it work. The 1/4” edging actually sounds to me like the smart thing for me to do. Thanks again. mike

-- (You just have to please the man in the Mirror) Mike from Michigan -

View Mark A. DeCou's profile

Mark A. DeCou

1973 posts in 3010 days


#9 posted 2785 days ago

Hey Guys: I’ve been busy trying to finish up Christmas orders, and so I haven’t checked on my forum topics lately. I agree with Woodwhisperer, I use the Unibond 800 glue for veneer, because this is what David Marks’ uses in his DIY Woodworks show. I do very little veneering, so I forgot to mention it in my glue listing. It is not the easiest glue to find, and I had to order it over the internet. Mike, if you have a hard time finding it, let me know and I will dig out my receipts from the last time I bought it and let you know where I found it. I just mix it like it says on the side of the container. It has a long “open” time, so it is David Marks’ selection for assembly glue when he has a lot of parts to glue up and doesn’t want any of it to set until the parts are all together. This glue needs to sit overnight to dry.

I also don’t like using veneer edging on something that has a chance of getting bumped by legs, such as your case box lid edge. The veneer joints at the corners are susceptible to being easily damaged by ordinary use in a room, even dragging a throw blanket and pulling it off can rip a corner of veneer edging, and the blanket.

In your case, my recommendation would be to use a strip of wood, the thicker the better, and use regular PVA wood glue to hold it in place. The other suggestions I agree with, as you will need to hold the strip in place while the glue sets. You can do this with multiple strips of masking tape, or you can use a brad nailer (not my choice) or you can use a pin nailer (I don’t have one), or you can use the long “caul” (strip of wood) that you use to apply even force along the strip you are gluing. A friend of mine (lumberjock Duane Kohles) has a pin nailer (no head nails) and says it works great, with no holes to fill with putty. Maybe he can enter a tool review about it sometime in the Forum. This tool is on my wish list for situations like you are encountering.

I have used the iron on veneer edging, but it does not hold well for situations where the veneer could get bumped, such as in the case of your box lid. I would use it for situations where I was covering plywood edges on a shelf board, but not in a structural situation. I am not a heavy veneering guy, as I mentioned, as there are just too many antiques with ruined veneer, so I generally try to stick with solid wood. I noticed that Karson added a new wall cabinet project, where he used veneer on the door panel, and that is the type of application where I think veneer makes a great addition to a project, giving wonderful grain in an expensive wood, yet is not in a situation where it would lift easily. I met some nice folks at the Western Design Conference that cut down a tree and had it’s wood made into veneer. They sent me as a gift about a dozen pieces of the veneer, and I will be using it in a similar project to Karson’s after Christmas is over.

Marc Adams has a great video on Veneering that I bought several years ago, and he says that any wood glue will work great on veneer as long as you have a method to hold it in place with pressure. In cases where that isn’t possible, he said a compromise is to use Contact Cement glue, as is done with Formica style counter tops for kitchen cabinets. Karson has what all of us wish for, and that is a vacuum bag. This is another tool that will eventually be in my shop, as it will open up lots of opportunties to new techniques for woodworking that are too difficult to accomplish with other methods.

Hope this helps, let us know if this is not clear,
Mark

-- Mark DeCou - American Contemporary Craft Artisan - www.decoustudio.com

View jockmike2's profile

jockmike2

10635 posts in 2851 days


#10 posted 2783 days ago

Thanks Mark, I think I’ll stick with the 1/4” purpleheart edging. I’ve actually got the unibond 800 glue and veneer, but I’ve never done it before, so since it’s near Christmas I think I should take the advice of the three wise men….. whatdaya think? mike

-- (You just have to please the man in the Mirror) Mike from Michigan -

View jockmike2's profile

jockmike2

10635 posts in 2851 days


#11 posted 2783 days ago

You know I’ve got a paslode finish gun and I could throw some one inch little nail in there, they are pretty small and I’ve actually matched the purpleheart with my timbermate and foodcolor. So it won’t be nothing to cover up the holes, they’re pretty small. Thanks again for everyones time. mike

-- (You just have to please the man in the Mirror) Mike from Michigan -

View Shopsmithtom's profile

Shopsmithtom

780 posts in 2799 days


#12 posted 2782 days ago

I arf to agree with everybody, and I always use a waterproof glue when I’m outside working on my woof.

-- Accuracy is not in your power tool, it's in you

View MichB's profile

MichB

1 post in 1806 days


#13 posted 1806 days ago

I was reading your post as I was searching this site for information related to glue and its uses. You see I have this antique wood bedframe that I am trying repair. I am not so worried about keeping its value, it is more a sentimental piece that I just want to repair for use by my daughter. Anyway, it is a structural repair. The footboard of the bed is split top to bottom with a crack. The crack runs across some molding – the footboard has 3 panels joined together and covered with moldings. Anyway I have been having this debate with friends over using wood glue like Elmers versus Epoxy. I personally thought that the Elmers would be too weak to hold the stress this area might take. I don’t want the seam to rip open and have my daughter with the bed coming crashing to the floor or something. So what do you recommend to use?

View LesB's profile

LesB

1060 posts in 2047 days


#14 posted 1805 days ago

Great information.
In regards to venneer I recall reading that PVA glue is not recommended because it can “creep” with time and cause the veneer to move. I don’t remember the source.
I have found the urethane glue works well on dovetail joints because the “foam” out is easy to clean up afterward without leaving spots that resist stain like PVA does. I use a small stiff brush to lightly coat one surface and dampen the other surface with a fine mist of water to activate it.

Does anyone have any experience with the hot glue guns (not the melted stick kind)? They are probably more suitable for production type assembly.

-- Les B, Oregon

View gerrym526's profile

gerrym526

265 posts in 2412 days


#15 posted 1805 days ago

Mark,

Great write up with lots of useful information.
What I would add to the discussion on PVA glue clean up is that using a damp rag around joints that have glue squeeze out doesn’t really weaken the joint. What does happen is that the squeezed out glue gets thinned out with water, and becomes “sizing” or wood pore filler around the joint. If you don’t do a significant amount of sanding to remove this almost invisible layer of glue around the joint, it will show up as an area that won’t absorb stain your applying in the finishing process.
Your technique of scraping away squeeze out around a joint when it has reached the “rubbery” stage of curing is the correct one.

-- Gerry

showing 1 through 15 of 18 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com

Latest Projects | Latest Blog Entries | Latest Forum Topics

GardenTenders.com :: gardening showcase