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Dave Strnad Posted: Dec 09, 2006 02:53 PM	Temp? Ok I know temp is important. My system is a little different, because I built it myself. I never really mess with the temp. So I guess my question is. If the foam looks good, sprays good, good yield, etc. is it ok or can temp affect things I cant see such as R-value, cell structure, etc. Next I know a lot of guys carry pocket therometers with them. I assume that they are sticking it in the foam as they spray. Is this correct? If so, if someone says they are spraying 120 F is that measured that way or just the setting on the equipment? If not what temps should you get by putting it in the foam as you go?
Posted: Dec 09, 2006 06:54 PM	i have a custom rig as well, and my experience has been that i can fudge the perameters of the foam by increasing/decreasing temp. For example, when I use foam enterprises winter foam which is rated for 45-60 degrees. by adjusting my temps i use it 40-70 degrees. With closed cell, when its too cold, the foam will still eventually react, but there is very poor adhesion. The foam closest to the substrate sort of crystalizes while the rest is good quality (yeild is also lower). We have tested tons of cold weather techniques to extend our season. Some have worked pretty well. I use a non-contact infared thermometer constantly when im pushing the temperature limits to check my surface temps befor spraying. How does your rig proportion the foam?
Dave Strnad Posted: Dec 09, 2006 08:56 PM	My rig seems to proportion and heat well. I used a Graco bulldog 32:1 Plural pump with two 11 gal tanks which hold my stainless heat exchanges and 10,000 watt heaters. It seems to be enough thermomass it will maintain temp as fast as I can spray. I need to work on my hoses though. I used 3/8" for my heating loop. I am planning on bumping it up to 1/2" next time I redo it or find a higher psi circ pump. To tell the truth I have never adjusted my temp. I set it at 125 on the return line of my hose loop and its been there ever since. The other day I sprayed some sheets of paper to make some foam business cards and I experinced the crystalizing that you talked about. It seemed that a thin layer stuck to the paper but the foam pulled away easy. That sort of made me nervous, I thought that it might be my settings and began to question all of the drywall that I've sprayed. It was extremly cold that day and I 'm sure the paper was well under 40.
Dave Strnad Posted: Dec 09, 2006 09:11 PM	One more question, when you said that when the temp is too low it crystalizes. Were you talking about the substrate or the material temp?
Posted: Dec 09, 2006 09:30 PM	substrate temp, if the material temp is too low i just get a stream instead of a spray. I sprayed a basement around the floor joists one time, and when we went back to scrape off the studs the foam just popped off from the crystalization. when i checked the substrate temp i realized that it was about 2 degrees too cold on the north side of the house. doh!
Dave Strnad Posted: Dec 09, 2006 10:01 PM	What kind of setup do you have? Liquid or electric heat? What do you use for a proportioner? Is closed cell easier to spray? I have only used nap closed cell so far. I have had good results. I was very nervous when I first got started. I was pretty much told that after I had spent 3 months putting everything together that it wouldn't work. Luckly for me and my marrige it has. LOL I still may upgrade someday, especially if I end up hiring someone to spray. I know my rig inside and out, but I think it may be hard for someone else if they were used to the other proportioners.
Posted: Dec 09, 2006 10:36 PM	basically heres the rig: -liquid hose heat -sealed A/B tanks (with descicant air breathers) -gavity fed fluid pumps powered by electric motor -husky transfer pumps (to get material in the tanks) -shurflo water pump to ciculate heat thru tanks and hoses -runs off 110v or 3500watt generator and 5hp gas powered air compressor -modified 3 gallon waterheater -Max-x air purge foam gun -250' hose
Dave Strnad Posted: Dec 10, 2006 08:03 AM	It is nice to see that I'm not the only one out there with a self made rig. I was starting to think I was the only one. My rig is pretty much an ebay special with the trailer and gap gun being the only new items.
Aaron Scurlock Posted: Dec 10, 2006 09:22 AM	I do not know enough to make my own rig. I wish I did. I am only doing polyureas at this time, but may move into foam...who knows?
Dave Strnad Posted: Dec 10, 2006 10:15 AM	It is not rocket science, however if i were to do it again I would probally just buy it. There are some good proportioners out there that are pretty reasonable. I happened to come across some of the equipment for next to nothing, otherwise I would have more into mine than if I were to buy new. At the time i really wanted into the biz but didn't have the funds. I just started selling everything I had. An old canoe finaced my proprtioner, bandsaw bought my air compressor, etc. I have to say I was pretty embarassed when I showed up of my first job with everything hanging out of a 4'x8' wood trailer, but it worked. My rig is much better now, I couldn't go without my insulated 7X14 trailer.
Melvin Chandler Posted: Dec 11, 2006 08:06 AM	What is your lower limit for surface temps?
Dave Strnad Posted: Dec 11, 2006 08:50 AM	I was told 40ish, but no one ever made that big of a deal about it. I was told that surface moisture was a bigger problem, and that with cold temps you get less yield. I was given techniques to help. Increase temps, spray a picture frame or thincoat, skip stud spaces, etc. I don't ever remember anyone saying don't spray if it is under or over a certain temp just techniques if it is colder or warmer than ideal. I will ask my rep next time I talk to them.
Brian Mulder Posted: Dec 11, 2006 09:48 PM	DaveS, I also use NAP foam and that is all that I have used so far. I am new to the foam biz. I just sprayed my first job three weeks ago and I had some cold mornings. It sounds like the NAP guys trained you. I have used the same tecniques you mention (from NAP)and seem to be doing just fine. The NAP crew has been great and they don't pull any punches teling it like it is. I bought my spray rig from them as well. What do you think is the coldest temp you have sprayed in so far? I just ordered 10 sets from them today and have three jobs to spray so I will be getting the chance to use thier foam in some cold weather. Do you use heaters in the house to warm up the surface temps and if so what kind and fuel type? My last job I used the kerosene salamander just to take the chill off and warm up the surface. To what temp I don't know. It was warm and I sprayed and it stuck and expanded. I use electric heat in my lines and do not wrap the scuff jacket in anything else to keep heat in. Is anybody adding any extra insulation to the hose or just going with the electric heat in the line. I see someone using water to warm the lines and that seems like it will add more weight and work to the equation. thanks and keep spraying. B
Posted: Dec 12, 2006 12:26 AM	i use water heat, and my hoses are wrapped in several layers of polyester membrane. its just the reinforcing membrane i use for my coatings. i use 5" by 300' rolls, and usually wrap the hose four or five layers. i spray in a lot of cold temps, and this has been great. plus its cheap to replace the outer layer when it gets all foamed or cruddy.
Brian Mulder Posted: Dec 12, 2006 09:19 PM	where can I get the polyester membrane? I would like more protection for my hose as well as help keep the lines warmer on those colder days. Is the water heat for your hose homemade or is it available from a supplier? thanks B
Posted: Dec 12, 2006 10:24 PM	I get mine thru the conklin company. I think most acrylic coating suppliers would stock it (united, nationwide, lapolla, etc).
Thomas Kasper Posted: Dec 01, 2007 10:11 AM	Dave, ND, or anyone with experience with hot water heated hoses... I'm thinking about using hot water heat for my hoses, but I'm unsure witch way to go. Do you use a "closed system" with say 10 psi on your hot water system? Or do you use a "open system" where you water just returns to a small tank and is gravity fed to the pump? Thanks
Dave Strnad Posted: Dec 01, 2007 09:42 PM	Tom, Even though it returns to the tank it is still considered a closed loop for all practical purposes. Because it is a loop that starts and stops at the same point, height is not an issue. What goes up must come down so all you need to overcome is the resistance of the hose. Similar to a siphon. I calculated all of this when I built my system but I don't remember the formulas. You can figure how many BTU's needed to maintain a specific temp and size the pump according to that. I used large heat exchangers so my water temp was close to the temp of the material so I used a larger circ pump so that I didn't have much heat loss from start to finish. It seems like I usually only lost 5 degrees or so on the lines.
quentin Posted: Dec 03, 2007 08:41 AM	Not sure but you may want to look at the UCSC Duraseal PolarPro 1.9 for colder jobs. Says the surface temp should be between 30 and 80 degrees. I saw an article where they designed it just for the colder time of year up in us more northern areas. Here is a link to their PDF specs. http://www.buyucsc.com/modules/PagEd/media/test/DATA_Duraseal_PolarPro1_9.pdf
quentin Posted: Dec 03, 2007 08:41 AM	Not sure but you may want to look at the UCSC Duraseal PolarPro 1.9 for colder jobs. Says the surface temp should be between 30 and 80 degrees. I saw an article where they designed it just for the colder time of year up in us more northern areas. Here is a link to their PDF specs. http://www.buyucsc.com/modules/PagEd/media/test/DATA_Duraseal_PolarPro1_9.pdf