It may help if you clarify what you consider natural and synthetic wood glues. Do you mean you want to be able to collect the ingredients in the woods for some reason? Is there a particular type of chemical or other component in wood glue you are trying to avoid?
Also, what are you glueing to what? Right now, I just know that you want a desktop and you don’t want to make legs. Does that mean you are setting this desktop on the frame from your old desk? Are you gluing boards together on edge? Are you don’t joinery? I’m pretty sure that the type of gluing is going to matter, especially if you’re trying to find a glue that has undergone minimal processing.
Yes, sorry! I had all that in there at one point… much too tired. Basically I want to avoid using polyurethane and PVA (a tall order, I know).
I haven’t ordered the lumber yet, but I plan on getting some 5/4 S2S soft maple.
I wish I had the tools and skills to do joinery, but not yet. I’ll be rough sanding the edges to get rid of whatever chafe is left and to fair them, then I’ll glue them edge to edge. I’ll then sand down the rest of it so that it’s all pretty much true, and finish with a spirit varnish.
Finally, I’ll drill pilot holes for the screws that attach it to the base of the desk.
Thanks for the details! I’m sorry to say that I don’t know enough to help you very much. I have never tried looking for or working with non PVA wood glues. I suspect that even with PVA glue, you would have a hard time getting boards glued edge to edge stay at all true, so keep in mind you are likely to end up with some warp and unevenness that may show up later…. Actually I just had an idea that I think would work well - get/borrow a pocket hole jig and use that to do your edge joinery. A pocket hole jig is really a great tool that is easy to use. Check this out. Kreg is just the most common brand of pocket hole jigs. There are cheaper ones out there, although I can’t speak to which other brands are good/bad.
In a couple other responses you mentioned not having the tools for joinery. I think it may be beneficial if you tell us what tools you do have access to.
PVA is going to be one of the strongest wood adhesives you can find aside from construction adhesive and I wouldn’t trust any furniture only held together with glue.
Typically you are going to use the glue in conjunction with either joinery or metal fasteners.
I have a drill (with bits), screws, sand paper, and a hand saw. I think now I will use pocket holes in conjunction with glue, or perhaps buy some dowels and use those.
Definitely go with pocket holes over dowels. Speaking from personal experience dowels are very hard to line up especially with a hand drill instead of a drill press.
I don’t know what your expectations for the desktop are, but with the tools you have at hand right now a rustic or farmhouse style desk would be the most reasonable expectation. Prepare to put in a lot of work and have small gaps between each board and a non-flat face.
To create a top that is perfectly flat and has no gaps is virtually impossible with the tools at your disposal.
If you truly want to build the desk yourself with the tools you have AND you need it to be perfectly flat you could do your absolute best to build it flat and tight and then place a glass top over the wood. Then you can admire working over something you built yourself and if you acquire the tools and skill in the future to make the top flat and fill the gaps you can refinish the wood and ditch the glass.
You may want to look into community woodshops or tool shares in your area. If available they will usually require you take a couple safety classes with their teachers so you know how to use all of the equipment and then a monthly fee for access to the tools and bench time.