Water soluble wood glue as MDF primer and much more.
Hi guys. I was in the need of spray painting some MDF pieces, and concluded that priming its a must before applying your paint, specially in the edges, which is where it shows more signs of porosity.
What I did was to dilute some water soluble wood glue, using this ratio 1:1, and then applying to the edges you want to seal and prime. I did 3 thin coats, and when dried I notice how the surfaces were actually more harsh, I did not get disappointed to soon, and gave just a little of finishing sand paper. Now the surface was extremely soft and nice, ready to receive the paint. By itself, the sand paper cannot do this, I tried before and it was difficult to get a soft touch.
I have not too much experience with wood glues, and actually always used those wood glues that are waterproof, not sure how good they can perform in this task, I have a gallon of water soluble wood glue (titebond classic) so I used it in first instance. Water soluble wood glues are the cheapest ones in the market, and you can get a lot when buying big quantity as a gallon or a bucket.
Another good trick I discovered, was that it's so easy play with the viscosity level of this glue, I was in the need where a glue very viscous was more convenient, for example sealing a sealed subwoofer enclosure in its corners, so now the glue does not drip and have more mass, I simply put some glue in a Tupperware or glass and let it seat for hours or days, I mix every 6 hours, because it tends to dry more at its surface, and because all the mix is water soluble, dried sections can be diluted just by the actual amount of water the mix has. Let everything dry until the desired viscosity level.
Its amazing how it dries as a rock, but can be molded or cleaned with a wet rag, I was working inside a subwoofer, and cleaned some messed parts with the wet rag.