This page is the result of the research I have done and my own use and tests. I was curious about the Titebond 3 that I had bought to try and wanted to know more about the PVA glues and answer for myself is PVA good for boatbuilding?
Poly vinyl acetate glue often referred to as wood glue or carpenter's glue, Elmer's glue or white glue is an aliphatic (non-aromatic organic compound, it does not have the benzene carbon ring structure) rubbery synthetic polymer with the general formula (C4H6O2)n. It is a type of thermoplastic.
A thermoplastic is a plastic material, a polymer, that becomes pliable or moldable above a specific temperature and solidifies after cooling. If heated too high it burns rather than soften any more and destroys it's chemical structure.
What is Poly Vinyl Acetate Glue, also known as PVA glue, used for?
Making PVA SLIME
If you take white pva glue and add a boron solution to it, a series of crosslinking reactions occur and a slimy goopy material is formed. This has been a favourite of kids everywhere. Here is one recipe:
- Mix 1 teaspoon borax with 1 cup water until the borax dissolves.
- In a separate container Mix 1/2 cup white PVA glue with 1/2 cup water with or without food coloring.
- Combine the 2 mixtures together stirring slowly.
- When it starts coming together you can mix with your fingers. Pour out any extra water.
Store in the refrigerator to prevent mold from growing.
PCV glue has a long history of use as a general purpose glue. The fact that it is non toxic, (see material data safety sheet link in Advantages section) glues most craft materials such as wood, paper, leather and cardboard and is easy to apply often supplied in convenient squeeze bottles has made it a favourite for crafters everywhere. PVA glue is water soluble and cleans up easily with water. It is the standard white glue of most schools.
Any number of non gluing craft applications have been developed including as a semi-gloss finish over decoupage, tranparency making material and as a goopy modeling clay/slime.
Most craft grade glue are not water resistant and will deteriorate in wet conditions. Most construction and carpenter's glue are type 2 water resistant. There is one glue that is classified as type 1 waterproof.
The main use of PVA glue is as a wood glue. It is the most commonly used non structural carpentry glue and there exists many different brands geared to carpentry and construction. White glue has mostly been replaced by yellow carpenter's glue because it is water resistant. Although it is mainly sold as a material that glues porous materials, some brands claim it can be used for some plastics, ceramic and metals. Anyone who has tried to chip dried carpenter glue off metal clamps can vouch for some metal gluing properties.
Because it can creep over time it is not used in structural applications such as beams. In these applications, Resorcinol, phenol or urea formaldehyde glues are often used.
Although most PVA glues used industrially are water resistant to grade 2, which means they can sustain several cycles of soaking/drying without having the glue fail, they are NOT Waterproof.
Titebond has put a PVA (Proprietary Polymer) glue (Titebond 3) which has been classified as a grade 1 waterproof glue capable of sustaining several cycles of boiling and drying.
The jury is still arguing if pvc glue is good for boatbuilding.
Since it has not been around for very long in terms of boat longevity, there is not a great number of boats which have been built with it.
Many boatbuilders have tested Titebond 3 and have reported on the various forums. Report for the most part appear to support the manufacturer claims.
What are the Advantages of PVA glue?
- Is rated as extremely safe. Here is the Material Safety Data Sheet for Elmer's glue PVA. Here is MSDS for Titebond III
- It has been in use for a few years and many people have tested it. It is reliable within it's range of recommended use.
- Some formulations are water proof to level 1 (boil proof) and several to water resistant level 2. It should not be used where it will be submerged for a long time.
- Relatively quick grip and short work time. Most PVA have an open time of around 10 minutes.
- Remains somewhat flexible after drying.
- Water cleanup before the glue is dried is simple and safe. After drying glue squeeze out can be chipped off.
- Widely available and relatively inexpensive.
- Glue dries to an almost colourless glue line to light brown in some types. Can be dyed with aniline dyes.
- Set glue is stronger than most woods it is gluing. 3500-4000 psi for the Titebond glues.
- Has a recommended shelf life of 1-2 or so years and can sustain SOME freezing.
- It is convenient, no need to measure or weight 2 parts. Un-used glue does not go bad.
What are the Disadvantages of Poly Vinyl Acetate Glues
- It can creep in high pressure/higher temperature situations.
- It does not have a long open time so if a complex gluing operation is needed then either glue in multiple steps, get extra hands to help you or use another adhesive.
- Any joint needs to dry after setting to reduce wood swelling caused by water. This can take a day or 2.
- Joints need to be good since the glue is not gap filling and clamping is required.
- It is a very nice glue to use if you are gluing up several boards to make a panel. I've used it to glue up a rudder blank for a day sailor, and it has worked very well.
- It is not recommended for long term immersion.
- No other glue will stick to it except Cyanoacrylates. Epoxy does not stick to it. Fresh PVA glue will not stick very well to dried set PVA.
So can PVA be used in Boatbuilding?
Many people have tried it and it works as advertised. It can take a great deal of occasional moisture but cannot be used in places where it will be submerged all the time.
It certainly could be used in a protected dry area that will not be submerged but might occasionally get wet.
Many boatbuilders have run extensive tests on Titebond 3 and for the most part the results are good and encouraging.
It is a difficult glue to glue TO so any repair would require the old glue to be cut out or removed. The only glue that can bond to it is cyanoacrylate glues.
If you are planning a boat that will be well waterproofed with epoxy or varnish, and that will be taken out of the water when not in use, then it could be used.
Before using Titebond 3 to glue up a dinghy rudder blank, I made up a sample and left it in water for several days. The glue held up with no problem and I decided to use it. The rudder and daggerboard have held up with no problems.
I don't claim to be an expert. I'm not an engineer or a chemist. I make mistakes. This page is not a recommendation of products, it is for information and entertainment. IF you want to build a boat with PVC glue make sure you use the material as instructed by the manufacturer. It is advertised as waterproof but not for long term immersion in water.
email me if you find mistakes, I'll fix them and we'll all benefit: Christine