On the EA-40 two-part glue container, it mentions a temperature of 73°, but I've seen online videos where bowyers bring their heatbox temperature way higher.
What is the recommended heatbox temperature for laminated bows when using EA-40?
and also,
What is the recommended duration of heatbox cook time?
Thanks!
I still run 180 degrees, only because the snap disc I bought from Elmont who knows how long ago still works.
I leave the form in 4-5 hours. I reckon if I built over 3-4 bows per year I might look into the heat strips or at least an adjustable thermostat.
Thanks so much! You're awesome. I appreciate it. I'm curious about the heat strips too! Please keep me in the loop if you find any that work well.
Quote from: kennym on September 23, 2025, 08:28:51 PMI still run 180 degrees, only because the snap disc I bought from Elmont who knows how long ago still works.
I leave the form in 4-5 hours. I reckon if I built over 3-4 bows per year I might look into the heat strips or at least an adjustable thermostat.
Kenny,
Does yours have 300 watt bulbs? 4 for the limb box and 3 for the riser? I think the box I have was made from those plans and I'm wondering if I should stay with the 300 watt bulbs or could I drop some of the wattage down, I'm in need of some new bulbs and was just getting ready to hit the checkout button when I seen this post.
Dan
I use 3 200 watt bulbs. I have found that getting the surface temp to 130 and letting them cool in the box works well. I always mix more resin than hardener also.
I have 6 bulbs, usually unscrew a couple, think they are 150s , On curvy bows I unscrew the end ones to protect the hose from too much heat...
Quote from: kennym on September 25, 2025, 07:58:08 AMI have 6 bulbs, usually unscrew a couple, think they are 150s , On curvy bows I unscrew the end ones to protect the hose from too much heat...
Thanks, Good idea about the outside bulbs.
I use heat strips myself. 160 degrees for 30-40 minutes will cure the epoxy. Another 20 minutes for cool down.
Hot boxes take much longer to get that epoxy cured. I used a Xmas tree timer on mine and kept the box at 180 degrees for 5 hours... you need a thermostatic shut off to regulate temp on those hot boxes that shut the bulbs off when it hits 180.
I use heat strips too. For 1-pieces I was starting at 120 and going up 10 degrees every 30 minutes too 160. After reading kirkl post I tried limbs for 3-piece 30 minutes at 150 then another 30 at 160. Seemed to work well.
Where is people getting the heat strips from? I might build a setup for 2" width if I can find them.
Quote from: TC209X50 on October 03, 2025, 08:47:22 AMWhere is people getting the heat strips from? I might build a setup for 2" width if I can find them.
I really can't help with where to buy heat strips. I used to sell them years ago when everyone was using the silicone heat strips. But.... The damn things were not very dependable, and life expectancy was all over the place. The company I purchased them from replaced a few of them under warranty at first, but they finally discontinued the warranty.... It was a nightmare. I finally gave up on them and started messing around with building my own low voltage heat strips using various ideas and controllers with some success, but no longevity. Then I stumbled on to someone using stainless steel pressure strips and a battery charger. I've used that system very successfully for many years now. The down side has been the chargers only last for about 150 bows. I got over 200 bows out of one though... Now it's getting harder to find the right type of battery charger that will work for this application. The new electronic chargers won't put up with the abuse, and have a safety shut off. Using a battery charger with a voltage regulator is serious battery charger abuse, and the only last so long...
If this is something you are interested in using email me at kirk@bigfootbows.com and I can provide a detailed step by step instruction I wrote up on how to set this up.... Kirk
I wonder if there would be a way to do it with a voltage regulator and plug straight to the wall(without starting a fire or popping your breaker)? Any electricians on here????
Quote from: Watsonjay on October 06, 2025, 01:03:01 PMI wonder if there would be a way to do it with a voltage regulator and plug straight to the wall(without starting a fire or popping your breaker)? Any electricians on here????
Something like a Wall Wart power supply should be able to do it, assuming it is properly sized for the power requirements. It would also provide better control over the voltage and amperage to reduce risk of shock or fire, etc.
Many of the battery chargers used for charging the lithium ion batteries used in radio controlled aircraft offer a controllable constant voltage/amperage power supply intended to be used for hot wire cutting of foam. If properly sized for the power requirements this should also work.
Mark
I honestly can't see those small ac/dc power suppliers being powerful enough to heat up a 22 gage piece of stainless steel 6' long, much less two of them. My set up has a voltage regulator and requires 40-65 volts to the charger.
I was thinking more of a small buzz box welder might be the ticket.
Quote from: Kirkll on October 08, 2025, 10:26:51 AMI honestly can't see those small ac/dc power suppliers being powerful enough to heat up a 22 gage piece of stainless steel 6' long, much less two of them. My set up has a voltage regulator and requires 40-65 volts to the charger.
I was thinking more of a small buzz box welder might be the ticket.
Well, properly sizing your power supply is the big trick. I wasn't suggesting that a wall wart would be big enough, just that that is the sort of power supply that people could look for.
A small welder might work if it gives you what you need in terms of volts and amps. Lots of the small ones only have a 20% duty cycle rating, so you would have to watch that as well to avoid problems there.
Mark
A lot of these newre battery chargers have a digital display and circuit boards with built in saftey controls that wont allow you to use them for heating up a stainless steel strip. It automatically trips a breaker well before you get any heat built up, and needs to be reset.
Trying to find the older style battery charger with manual controls is getting harder to find anymore. If someone comes up with a better solution i'm all ears. Kirk