From Gluing & Clamping: A Woodworker's Handbook:Bill
My copy of 43.13 is the 1965 version when Weldwood Plastic resin was what the pros around here were using (so that's what I used). It was one of the recommended glues back then along with resorcinol. Anyway, Ch 1 Sec1 para 5 says sandpaper must never be used to smooth sortwood surfaces to be glued. That's where that came from.
In edge gluing, you're bonding to the side of a bundle of straws. Sanding the bundle of straws gashes the sides of them open or crushes the cells. There is more on this in the Forest Product Laboratories Wood Handbook.So how is that fundamentally superior to sanding which leaves shallow troughs by removing a little extra of the softwood randomly.
How much of it do you use? Can't you acquire your own clean containers which you ship back to the supplier empty each time to be refilled with technical grade? Might be worth looking at if the difference in cost between the grades is significant. Sorry about the slight thread drift.At my current employer (for 3 last days yet!) we had a major issue with acetone purity. Our specs only required "technical" grade for pre-bond or pre-paint cleaning. However our specs did not address container purity or contamination... we learned that our acceptably pure technical grade was being shippen in tank cars and drums that were reclaimed and there was not control over the prior contents! we ended up changing the specs to require "reagent" grade - a much more costly grade, but a grade that comes from the manufacturer in known clean vessels. Subsequent to that issue we had in-house repackaging to smaller bottles - that turned out to be insufficiently solvent resistant and they woudl very slowly breakdown on the inner surfaces, yet again contyaminating the solvent. Today only reagent grade, in the manufacturer package acetone is allowed for pre-bond and pre-paint cleaning!
I am yet workign for the capital B - and we use vast amounts of acetone. the actual problem was that the vendors did not need to ship clean because hte spec does nto requiere it and the spec custodian(s) said thye woudl not change the spec since we were buying a clean grade and no one would ship a clean grade in dirty vessels...! stupidity on both sides of that coin.How much of it do you use? Can't you acquire your own clean containers which you ship back to the supplier empty each time to be refilled with technical grade? Might be worth looking at if the difference in cost between the grades is significant. Sorry about the slight thread drift.
In my post life, when we (me and one of my buddy) were gluing aqau-tanks, after acetone you have to wipe it with gasoline solvent. One of easiest to find supply - good quaility lighter fluid, like Zippo 3141EX or similar. It have to come from metal can and no yellow color.Now to acetone. It is a nice solvent if it does not have oil in it, as observed by other folks. I attended a session on repair of composites some time back, and the trainer recommended wiping a sample of your acetone on a clean glass surface and watching it evaporate. If it does not leave the glass as clean as it started, it has oil remaining from the distillation process. This oil will interfere with bonding. The only acetone his aerospace repair facility allows on site is reagent grade acetone. Yeah, it costs more to distill the acetone to that level. You know where the impure condensate from distilling goes? It becomes hardware store acetone. Alternatives are other solvents, which should also be checked by the same methods, but are way more likely to leave really clean surfaces.
The more I hang around here the more I realize how little I know!
The wood handbook was based on adhesives that needed really good fit up, nicely planed surfaces, and serious clamp loads. We have T-88 and West, which will fill gaps, do not need much clamp load, and will give you glue joints that will hold better than the wood for longer than anyone you know will live. Be happy...Yeah, a bit scary reading all the details in the Wood Handbook.