Bicycle Mechanics - Watching Paint Dry - Come Join Me. :)

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JoeTown244GL
05-20-05, 07:02 PM
I've torn down an 80's Schwinn Le Tour to the frame. It is to be my Grocery Getter / Night Bike / Rain Bike / Tractor Pull Bike. I've sanded the frame, fork, and neck and ground off some kickstand metal. I've applied a good quality rattle can auto primer and three coats of some really nice looking yellow enamel paint. (Ok, Yellow was an impulse choice. But it looks great) I now have the painted parts in a frame sized wooden box with one 150 Watt Hallogen light for heat. On the inside surfaces of the box I have glued that car windshied reflective silver stuff that you use in the summer to keep your car from melting and your dash from cracking.

Now the box is baking at about 170 F. I placed a latte thermometer through a hole in the top to measure the temp. There is a slight gap at the top of the box where some serious fumes are outgassing. So, how long do you think it would take to fully cure the paint?

PS - I had two Hallogens in there at first and the empty temp in the box hit 190 and was still climbing strong. I had this vision of my house burning down and me trying to explain what I was doing mixing heat and hydrocarbons in a box to the arson investigator. Yep, prison was just a few degrees of temp away.

So, anybody else ever try to hasten the cure of paint with this method? Will the paint harden more than rattle can paint normally does? Or, am I just a danger to myself and others? :)


fsor
05-20-05, 11:53 PM
You do not want to flash the solvent that carries the paint off so fast that you get bubbles...it seems that you have avoided that. Generally, if the paint goes through a cross-linking reaction (epoxy and some urethanes) you will get a slightly harder more resilient paint by this post baking. For the techies....your Tg of the amorphous phase approaches that of the cure temperature....but this is likely just a varnish type paint and the baking process that you executed just dried it out quicker.....in this case it is harder than a green paint job, but not hareder than an aged green paint job....it was still a good idea because you took it to true dryness a lot quicker.....sounds good to me. A typical rattle can paint job can actually take a week or better to totally dry... so you done good in my estimation

jeff williams
05-20-05, 11:58 PM
yes..in the oven for components etc.