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How hot can it get?


TMann

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Dang! -15F on the drive in to work.

 

My basement stays pretty much around 60F (which beats the hell out of trying to build in the garage right about now.) I have two twin size electric blankets that I throw over my parts while they cure. I'm thinking I should go by a couple of cheap quilts aor maybe put poly over it (or both) to try and keep the temp up.

 

I've noticed with parts that I was able to completely wrap with the blanket it seems to work well, but I'm not so convinced in the case (the canard for example) where I fold it over lenghthwise and lay it on top, that it is enough, hence my thoughts on more extensive measures.

 

Anyone have a method that will do a better job of raising the temp?

If I could get it up to the 100-110F range, I think my results would be better but most of the heaters I've looked at prevent that from happening.

 

I thought at one point I could use a baseboard type electric heat but I believe they limit you to 80F on the thermostat.

 

As a sidenote, I'm vacuum bagging most everything so the heat is an important part in getting the best epoxy to glass ratio. I'm rebuilding my canard and hopefully will finish the bottom skin this weekend. Looks like I'll be buying blankets at a minimum.

 

I also use this technique during the summer. I did some layups in the garage when the heat was +100F and while it was real uncomfortable, the results were great! Now that I'm working in the basement, It's pretty comfortable for me all year long but maybe not the best for composite results.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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Dang! -15F on the drive in to work.

 

My basement stays pretty much around 60F (which beats the hell out of trying to build in the garage right about now.) I have two twin size electric blankets that I throw over my parts while they cure. I'm thinking I should go by a couple of cheap quilts aor maybe put poly over it (or both) to try and keep the temp up.

 

I've noticed with parts that I was able to completely wrap with the blanket it seems to work well, but I'm not so convinced in the case (the canard for example) where I fold it over lenghthwise and lay it on top, that it is enough, hence my thoughts on more extensive measures.

 

Anyone have a method that will do a better job of raising the temp?

If I could get it up to the 100-110F range, I think my results would be better but most of the heaters I've looked at prevent that from happening.

 

I thought at one point I could use a baseboard type electric heat but I believe they limit you to 80F on the thermostat.

 

As a sidenote, I'm vacuum bagging most everything so the heat is an important part in getting the best epoxy to glass ratio. I'm rebuilding my canard and hopefully will finish the bottom skin this weekend. Looks like I'll be buying blankets at a minimum.

 

I also use this technique during the summer. I did some layups in the garage when the heat was +100F and while it was real uncomfortable, the results were great! Now that I'm working in the basement, It's pretty comfortable for me all year long but maybe not the best for composite results.

 

Greetings T.

 

You can build a heat tent over your parts. Consider using PVC pipe and a layer of 6 mil plastic on the outside of the framework and one on the inside of the framework (to act as an insulator) then you can use a relatively small electric heater (with fan) (I think that they call them "milking heaters") to raise the temp to the desired, at relatively little cost. You can make the frames as simple or complex as you want to allow a one time or multiple uses.

 

Fairly cheap and if designed properly, easily stoable when not needed. Since you will not be in the area much of the operational time use proper safety precautions.

I Canardly contain myself!

Rich :D

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TMann,

 

I used a pair of twin size electric blankets on my canard in my garage (back in N. California) where the garage temps were still colder than your basement. I measured the temp under the blanket with a remote thermometer. I gained about 10 deg when I topped the electric blankets with space (survival) blankets. It is mylar (?) which is orange on one side (with survival directions) and aluminized on the other side. I picked them up at REI.

 

Ron

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Thanks Ron. We're on the same page.

 

I may have to do both the heat temt and blanket to get where I want to be. I can try a couple of otions out before I do the actual layup.

 

Too bad sauna heaters are so expensive. :)

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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G'day

 

I recommend using an old refrigerator or freezer that doesn't work. I placed a 60 Watt light bulb in a 17 cu ft frig and it keeps my epoxy above 80 degrees when the hanger is around 35 degrees. The junk yard is a great source. If you cut the side out of two top load freezers and placed two 100 watt light bulbs in them you could have your own version of the Easy Bake Oven (EBO). I put a cheap digital weather station that gives inside and outside temp on my storage box. I put the outside probe in the frig. I get room and heatbox temp and time for about $10. You can very the temp by using bigger or smaller watt bulbs.

 

 

Just a crazy idea, but crazy is as crazy does....

 

Jeff

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:) Jeff, I have a heat box for my epoxy pumps (I have two).

 

I'm trying to raise the temperature of the part during the cure.

I'll have to think a bit on the Idea of fitting my canard into the fridge.:D

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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At 15 below it is quite literally cold enough to freeze the balls off a brass monkey,

Explanation follows:

It was necessary to keep a good supply of cannon balls near the cannon on old war ships. But how to prevent them from rolling about the deck was the problem. The best storage method devised was to stack them as a square based pyramid, with one ball on top, resting on four, resting on nine, which rested on sixteen.

 

Thus, a supply of 30 cannon balls could be stacked in a small area right next to the cannon. There was only one problem -- how to prevent the bottom layer from sliding/rolling from under the others.

 

The solution was a metal plate with 16 round indentations, called, for reasons unknown, a Monkey. But if this plate were made of iron, the iron balls would quickly rust to it. The solution to the rusting problem was to make them of brass - hence, Brass Monkeys.

 

Few landlubbers realize that brass contracts much more and much faster than iron when chilled. Consequently, when the temperature dropped too far, the brass indentations would shrink so much that the iron cannon balls would come right off the monkey.

 

Thus, it was quite literally, cold enough to freeze the balls off a brass monkey.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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:) Jeff, I have a heat box for my epoxy pumps (I have two).

 

I'm trying to raise the temperature of the part during the cure.

I'll have to think a bit on the Idea of fitting my canard into the fridge.:D

Build a cover (box) with cheap styrophoam... put one or two heat lamp in it (strap to the top)... with a fan...

 

Just an idea

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You can build a box out of styrofoam and sheetrock and heat it with lightbulbs, as others have said before. Doesn't necessarily need a floor so you can put it over the parts.

Also invest in some sort of electronic thermostat so you can keep the temperatures at exactly the desired level and even ramp the temperature up at predetermined rates. I used to improvise such a heating chamber using the corner of a room and three pieces of styrofoam, two lightbulbs, a dimmer, an electronic kitchen thermometer (5 bucks) and a PID temperature controller (dumpster diving, optional and not really needed). Worked very well.

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Thus, it was quite literally, cold enough to freeze the balls off a brass monkey.

Yep. love it. I read that somewhere else. The older I get the more interested I've become in etymology. Living in OZ with all it's old slang and also having to explain some of the US slang has certainly started some interesting conversations.

 

Back on topic...

My electric thermostat goes up to 35C or 95F. So that's where my hot box stays. Because so few OZ houses uses electric baseboard heat, it was very difficult to find a 220V thermostat. This one end up costing me $50. It's digital. That's nice, but when the batteries die every few months the lights go out.

 

So you could use a thermostat inside the heat tent that controls something like a hair dryer. That should get the heat up to where you want. Check the amperage of the heat source and thermostat. It may not be rated for that much current, but that could be solved with a relay.

Drew Chaplin (aka the Foam Whisperer)

---

www.Cozy1200.com - I'm a builder now! :cool:

---

Brace for impact...

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I'm bagging the forward nose hatch cover. I have it between a doubled ove electric blanket set on high with poly over the top. It's at 105F right now. If I could work with that range, I would be happy.

 

Tomorrow I'll get 2 sheets of 4' x 8' x 2" polystyrene and make 2 segments 10" x 14" x 48" (inside) which will give me a total volume to heat of just under 12 cubic feet. I think that should be something the blankets could handle.

 

The problem with most of the theories I hear all come back to the same thing, the thermostat. I can find heat sources, it just a matter of how to control it. The blankets don't seem to have the capacity to break 110F so I think I'm okay.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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D

I thought at one point I could use a baseboard type electric heat but I believe they limit you to 80F on the thermostat.

 

This can be changed by opening up the thermostat and finding a little set screw that limits the travel of the bimetalic temp sensor. I use one of these to keep my epoxy pump box at 105F.

Rui Lopes

Cozy MkIV S/N: 1121

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I built two 4-sided boxes out of 2 inch foam. They butt together to make a 13 foot long enclosure. I put my old canard in there with the two electric blankets and a glass of water. I sealed it up turned on the blankets and let it sit overnight.

This morning I pulled out the glass and dropped a candy thermometer in and it came up to 87F. I was expecting higher numbers but considering the air in the box is in the mid-80s, I don't think it would be a stretch to assume that under the electric blanket would be another 10-15 degrees warmer which brings me in at 95-100F.

 

I think this will work. In the meantime, I'm going to investigate the thermostat on the baseboard heater adjustment Idea. I may need it when I get to the wings.

 

My basement stays pretty cool in the summer. I supplement with heat even in July.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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To completely cure epoxy resins and reach a high Tg you need higher temps than just 38°C/100F. Unless you use the fast West System, whose Tg isn't much higher than room temp anyway...

The MGS 285 resin for example absolutely requires curing at higher temperatures to reach its full potential. Same is true for ALL other resins using such slow hardeners. Curing a part made with epoxy with 90 minutes of pot life at 80-100F will leave it right in the middle of the brittle B stage.

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To completely cure epoxy resins and reach a high Tg you need higher temps than just 38°C/100F.

Understood that in an ideal environment this would be the case however in a homebuilders environment this is not practical. You can only cure your parts in the environment you have and then wait for summer when you can post cure them in the sun to get the results you speak of.

 

At this stage, I'm trying to maintain enough temperature to get the most out of the vacuum bagging process. (i.e. improve the transfer of excess epoxy from the layup into the bleeder/breather layer.)

 

Anyway, I think I'm at a point that is pretty much in balance unless someone has a 6' x 13' sauna I could rent out for this layup? :cool2:

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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  • 1 month later...

A product used for keeping reptiles may be usefull for you, it's a product called flexwatt and is a flat heating element like what is used in heating blankets, you order it by the foot and can control the temps with a dimmer. being able to order 30' or so of it and put it on the top and bottom of the canard may be usefull. manufacturer recomends max temp of 95F but with carefull testing you may be able to go above this.

http://www.beanfarm.com/heating/flexwatt_userinfo.pdf for info

http://www.bigappleherp.com/Flex-Watt-Heat-Tape?sc=2&category=14 decent source, thought there are others and you should shop.

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