Comparing White and Yellow Glues

Differences may not correspond with color the yellow coloring is not an active ingredient. December 2, 2006

Question
Are white PVA glues stronger than the yellow PVA adhesives (modified with aliphatic resins), if they are similar in all other aspects?

Forum Resposnes
(Adhesives Forum)
From contributor E:
The yellow in the PVA is just a dye and put there for marketing reasons. The term "aliphatic resin" is also just a marketing term.



From Professor Gene Wengert, Sawing and Drying forum technical advisor:
There is a big difference between white and yellow glues, and it is more than color. The yellow has a higher instant tack. The yellow does not like to be moved once the pieces are joined. With an aliphatic resin, there is a chemical reaction that occurs that cannot be fully reversed with the addition of moisture.

Both white and yellow glues are stronger than the wood itself. Neither one will work well if the wood surfaces are not very close to each other (0.006 inches). Technically, an aliphatic resin is a group of organic chemical compounds in which the carbon atoms are linked in open chains. Aliphatic resins would be non-aromatic.



From contributor A:
White glues dry much softer than yellow glues and hence, are awful to sand. Over time this property can cause visual glue lines to appear with wood movement. The yellow glues are more brittle, but are very easy to sand. Strength is a non-issue because they are both much stronger than the wood, as mentioned. Personally, I use whatever glue is closer, but I really don't like to sand white glue.



From Professor Gene Wengert, Sawing and Drying forum technical advisor:
Although it is dangerous to put all yellow glues into one category, the white glues soften with heat much more easily than the yellow glues.


From contributor R:
Gene, contributor E is absolutely correct - it is just a dye that is added to the glue! Titebond and Titebond 2 have the extend version - they are white/off white. Franklin also makes an industrial product called Multibond 2000 - it is also white and it is just like TB2. It's just a dye, and "aliphatic resin" is marketing BS - both white and yellow glues are PVAs. As for the higher initial tack that yellow glues have, explain Titebond wood molding glue - it has the highest tack of the Titebond family and is a white glue! It's just a dye!


From Professor Gene Wengert, Sawing and Drying forum technical advisor:
The color is indeed a manufactured color that has nothing to do with the adhesive's properties. I have no problem with that statement and never said otherwise. What I said was there is more difference than color. Titebond is more than just Elmer's glue with dye added.


From the original questioner:
After reading a few articles as well your views, I am of the opinion that some yellow adhesives are really modified, whereas some may not be. The really modified ones are those compounded with certain aliphatic or similar resins to improve the qualities as well as drawbacks of the white glues. The really treated ones do possess extra tack and also easy for sanding. They also exhibit more water resistance. No wonder they are more expensive.


From contributor R:
Color has nothing to do with it. These glues that are modified to improve characteristics can also be white. For example, Multibond 2000 (white glue) sands better than Elmer's carpenter glue (yellow glue).

Again, it does not matter what color it is, white or yellow. Some yellow glues are harder than some white glues and vise versa. Take the glue on its own merits and don't worry about the color - worry only about the properties - i.e. sanding characteristics, initial tack, bond strength, open time, closed time.

So the answer to the original question still remains that color, white or yellow, means nothing because the glue is colored for mainly marketing reasons. For example, Titebond and Titebond dark wood glue are identical products with the exception of color. That same Titebond could be made white and still have the same identical properties as its yellow counterpart.

"White glues soften with heat much more easily than the yellow glues."
"The yellow has a higher instant tack. The yellow does not like to be moved once the pieces are joined."
"The yellow glues are more brittle, but are very easy to sand."
"White glues dry much softer than yellow glues and hence, are awful to sand."
These statements may or may not be true depending on which glues you are comparing.