Micro fill

[David]

Need some opinions. I have read that epoxy temps should be maintained 65 degrees or above for several hours after a layup. I have done all my structural layups with temps in the 80 degree range. My question is about the micro fill (non structural) stage only. Will temps in the 45-50 degree range effect the quality of the micro fill? I have placed excess micro in the freezer to slow the cure  and used it a day or two later. If I did not use it for several days it cured even though it was still in the freezer. Just wondering if I have to fire up the heaters to do a micro fill only.

David

[cts]

David,

Personally, I do not like to work in 45-50 degree temps (C or F!). So, this is speculation. I think that you might have problems with the problems with the micro not adhering to the skin surfaces. I think it will tend to roll up and be harder to work with. You can try spot heating with lamps and hir dryers to make working with the micro easier. You might also try tenting the immediate work area. I don't think that there will be physical differences in the final cure.

I would still tend to want heat the work area so that working with the stuff would be easier.

cts

[Bruce Hughes]

Hi David

If you are using West System fast hardener, be careful about
heating it; WS tends to give an exotherm unless you do a very good
stirring job.

You can paint a little epoxy on the surface to help the micro stick
but that wastes a lot of paint brushes and a little epoxy.   Try it
and see what you think.    

Bruce Hughes  

[David]

Thanks for the reply guys. I am not talking about filling a large area in these temps. I was just curious if anyone had noticed a problem of any kind filling in the small areas that were not filled high enough on the initial fill. Would hate to find out later that the bond was not good enough! By the way I am using EZpoxy.

David

[cts]

I have not noticed any problems and have done fill work in temps down to about 55 F without a heat tent. I do not like to do it but have.

cts

[Mick]

Hi David,

As many have said you will probably get away with it.

However that been said I would aviod it, as the temperature drops below ideal the molecular change is inhibited due to increased viscosity. So what you end up with is a partial cure, it may look like it has gone off but it probably hasn't completely. Down the track you may find that there is shrinkage of the micro after you have finished the job leaving an aesthetic blemish.

Take a look at any light weight final finish just after completion, it will, if blocked back look like a mirror. Go back in a few years and look at the same finish and London to a brick you'll be able to see the print through of the glass cloth. Same process.

You've probably completed the touch ups by know so it may be to late, but if not it is dead easy to make up a tent and run a blow heater for awhile. Then you'll sleep sound at night knowing you've done the best you can.

regards
Mick

[rglos]

David

Sounds like you're doing some work in the garage.

For small area work try an electric heating pad. For larger areas, an electric blanket.

Both are low cost. Just put some construction plactic over the area before you apply the pad.

Rick