KyleB15

My Feedback: (2)

Well after building a spad3d and crashing it several times all do to orientation loss i got tired of rebuilding found the Kadet and i want to build that so i can help myself and have a plane that i can fly slow and easy. What is falshing? Do i have to do it? It seems like i only have to do it when coro is glued to coro. Please help

JuniorPilot

ar you building the spadet? flashing can be for more then just coro to coro it's used to clean the surface right?

avistar181

flashing is using a butane or propane torch to "flash" the surface of the coro. This process burns away the oils in the plastic that are embedded from when it was manufactered. The oils prevent the glue from sticking and hence, need to be removed prior to any joining of coro. Heres a link to the men who invented spad and thier instructions on how to "flash" coroplast, Good Luck!![link=http://home.comcast.net/%7Etipstrickslinks/tip_flashing.htm]Flashing and Gluing[/link]

Crash Master

With flashing, you have got to use a low flame and move fast enough to not melt the coro, but slow enough to evaporate the oils in the material.

There are alternatives to flashing. Light sanding followed by a good rub-down of acetone has worked for me when I first started building SPAD's. Actually, the first one I built I did no flashing or sanding. I just used Household GOOP. It took a bit longer to for the GOOP to setup, but it leaves you with a good joint that stays flexible - unlike CA joints that can be more rigid and sometimes more brittle. There is also a Plastic CA out (available from HandiBond) is was developed for coro use. I have tried this on some scraps and it works pretty well if the joint is wiped down real good with acetone. An untreated joint didn't do so well.

Hope this helps,

Ross Kean

An assumption has been made that flashing is done to burn manufacturing oils out of the plastic. Although there may be oils present due to post-manufacture handling, buzzing a torch over the surface would be a lot less effective than using a solvent such as acetone. Flashing with a BLUE propane or butane flame actually chemically modifies the coroplast surface so adhesives such as CA will interact with the surface (stick). The presence of highly reactive ions and free radicals in the flame has far more to do with the change than heat. Heating with a heat gun has absolutely no effect and "flashing with a cool (yellow) flame will probably do more harm by leaving a sooty residue. Commercial treatment of coroplast to enhance adhesion of glue, ink or paint involves low temperature electrical "corona" discharge to have a similar chemical effect on the plastic surface. Solvents may help with adhesion by removing contaminants and scuffing with sandpaper will definately help any glue "lock in". Chemical CA primers will also help in some cases - I think Locktite has a product that some people have used with success.

Ross

KyleB15

My Feedback: (2)

Why am i building the Kadet, so i have something to fly slow and practice on. I did fly the Spad 3d but i lost orientation almost everytime i flew. Well thanks guys. I think i will just try sanding and acetone. Will paint thinner work?

rchawaii

Ross is right of course about flashing changing the molecular structure of the coro surface. Anyway I use sandpaper and wipe clean, I dont think thinner will do it, get some acetone and use some scouring pads on it if you have them and clean it when your done. Different methods work for different folks -ya gotta experiment to find what suits you and your environment. The source of the coro can also make a difference.

ChrisSpad

if by paint thinner you mean mineral spirits, it works fine, so long as you scuff the coro with scotchbrite soaked in mineral spirits.