Low cure pre peg and curing methods

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#1

I was looking low cure prepregs and these are used under normal vacum bagging pressure (29Mhg).

Now i have a decant work area and was hoping if i built a small room big enough for the largest parts i would make that would be the room to cure in

Now here is what i was thinking to use to cure the prepreg, in automotive industry infared lighting is making big noise, the last major bodyshop i was at had a both that fully used infrared curing systems. The inital cost for a booth using that was 40,000 uk pounds. But the cost of a bake was 4 pounds.

You can buy portable infared lights for alot cheaper 200 pounds or so any body on here had the idea of infa red curing

#2

Yep and it works good. Also heat lamps work good too so long as you have a few thermocouples. Infra red can actually be pretty bad ass as it cooks hot and fast. Used the lamps a ton in the military curing epoxy and adhesives. Also used lamps for backside heat and water extractions. They will heat a small room up fast. Don’t burn your house down.

#3

Its not in my house i do have experiance with them in bodyshops when we was priming out of the oven (rapid repair shop where 4 ovens where constantly in use 24 hours aday for paint jobs)

So do you think the infared would be a good option to use

#4

I think it would work… But those things pull alot of electricity… Why not get a used oven?

#5

or build an oven, it’s not that hard, or expensive. Wooden/steel frame, some rockwool and sheat material, heating elements and a fan or two.

At my workplace I have an oven in wich the whole car fits. It can be devided in 2 spaces for smaller parts, I hardly use the whole space. I use a Variable temp. system, I normally cure at 85 degrees celcius, can go as low as 65, or as high as 120.

#6

Also infrared can cure in irregular patterns. It is so easy to burn one spot, and have a cool spot right next to it.

#7

Yep Herman is totally right

#8

Yes im aware of this to but there are lights that when set to the right distance evanly spread the heat

#9

Low temp prepregs can be intially cured at low temps, but usually still require a higher temp post cure. So you would probably be best to construct or buy a oven. Benefit is low cost tooling with low temp prepreg.

#10

Usually it gives a lower surface quality when curing and later postcuring.

#11

if left unsupported, and depends on the resin.

#12

there are low temp prepregs that are designed for excellent surface quality.

#13

If left unsupported, offcourse, but why would you cure at lower temperature then, and not do the full cycle at once?
I use a system wich can cure as low as 65 degrees celcius, I used it for prepreg in a polyester mould. surface quality was ok, Tg and other mechanical property’s where not. After a postcure they where, but there was a printtrough in the surface.

#14

At one of my previous jobs we built a demonstration piece that we would take to Sampe and a few boat builders expos. It was called Boat IN A BOX.
Basically we took a wooden shipping conatiner and lined it with aluminum backed insulation. We would ship everything we needed to set up the booth, 5 foot dingy mold, table, prepreg, cosumables, vacuum pump, heating element, etc. The shipping container was the oven, we used a heated fan that would get the box to 180-200F depending on how far away we placed the fan. It worked great and to my knowledge is still being used today.

#15

Many consumables degrade after a resin cures, and then is post cured. I’ve had parts tossed because the peelply and bagging melted onto the part. if i cured, and rebag, it does not happen. Unless you have an expensive high-temp capable mold, then can’t toss the mold in an oven to cure/post-cure if it can’t handle the post cure.