Building a Powdercoat OvenPowdercoating is an excellent coating system, superior to paint in many ways, and is now available to the hobbyist through the coating guns offered by Eastwood, Columbia Coatings, Harbor Freight, and others. The main deterent to hobby use, though, is the fact that the coated object has to be baked at temperatures as high as 450 degrees, and for time periods up to 25 minutes, depending on the type of powder used. For smaller objects, an old kitchen oven can be used, but when the size of the object increases beyond that which will fit into a kitchen oven, the equipment cost goes up at a breathtaking rate. One of my hobbies is restoring and riding old three-wheelers, four-wheelers, and motorcycles. The kitchen oven I have in my shop will barely accomodate a wheel, and a swing arm would be out of the question. I decided to build a powedercoat oven to use in coating objects up to the size of an ATV or motorcycle frame. I wanted the oven to be collapsible so that it could be stored away when not in use. There's not much hard info on the internet about building ovens, but I contacted a few people that had experimented with this sort of thing, then made a few decisions of my own, and forged ahead. The oven is assembled from a series of panels which is actually 2" rigid fiberglass board wrapped in 28ga sheetmetal. Each panel is different from the others, but all have at least one dimension of 36", which is the largest size that my brake will handle. All fastenings are steel pop rivets, except a few screws which hold the panels together to form the oven. The base is a lightweight frame built up of light gauge metal drywall studs, with burner pans filling in the open areas of the frames. Heat is provided by 4 salvaged kitchen oven burner elements, of about 3000 watts each This was the real uncertainty for me, whether the element would heat up the large volume quickly enough. As it turned out, the oven heats up to 450deg in about 10 minutes. Temperature control is provided by a scrounged kitchen oven thermostat which controls a 50 amp definite purpose contactor to turn the elements on and off. The temperature floats a bit but it seems accurate enough. The total draw of the heating elements is about 12kw. My local power rate is 8.7cents/kwhr, so the oven would cost about $1.04 per hour to operate. Home Here is a front view of the oven. Inside dimensions are 24" wide x 36" high x 72" deep. Two of the four heating elements are visible. The shiny bar across the bottom about 1/2 way into the oven is actually an intermediate support member. It might not be clear from the picture, but the elements are recessed about 1-1/2" below the front lip of the base. A pair of rails, made from small channel iron will be laid the length of the oven and a trolley will be used to carry the coated object into the interior of the oven. I would use 1-1/2" angle so that the wheels would protrude at the bottom more... Scroll down a little further. If I were to do it over. .Home The trolley is made from 2" angle iron with 4ea fixed casters. The various rods and pipes that protrude upward are for supporting the items to be coated. The rails mentioned earlier are in place and visible in this picture. .Home and we have a picture of an ATV frame mounted on the trolley and being loaded into the oven. .Home Here is a wheel being loaded on the trolley. click here to go to the Construction Page. The fabrication of heat producing equipment such as an oven is an inherently dangerous process. a part also taken directly from the kitchen ovens. These windows were salvaged from two scrapped kitchen ovens. The owner of the website is not a professional engineer or designer. . Under no circumstances shall the website owner be responsible for any loss or damages.Home A picture of the top of the oven showing the view windows. DISCLAIMER This website is presented for the enjoyment of its readers only. nor does he purport to offer advice or consultation on the subject of oven construction. regardless of severity. For a closer look at how this oven was constructed. Anyone considering the construction of such an oven should consult the appropriate professionals for preparation of a qualified design. The black box on the side of the oven is the interior light. that arise from the use of information published on this website. Installation of electrical components requires specialized knowledge of the trade and of electrical codes. obviously a low budget model (I actually paid $50 for it at a welding shop). The main tool needed is a sheetmetal brake. Apparently some previous owner had bent the original and fabricated a homemade leaf. I think discussion of a few tools is in order. . Capacity is 36" wide x 18 gauge. This type of brake is slow to use and doesn't (in my opinion) make the sharpest bends.Home Construction Page Design Page Material List Contact Links Details of Building the Powdercoat Oven Before we start the actual construction details. Those of you familiar with this type of brake will notice that the clamping leaf is not stock. but I have my doubts about whether it could handle 18 gauge steel. Here is a picture of my brake. but it is tolerable for the purpose here. The base is constructed from 3-5/8" metal drywall studs. Other than the brake.Constructruction Page A few of the hand tools used for this project. . A shear would have saved a lot of time and made squaring the panels a lot easier. Click on this picture to view a larger size. Not shown is a drill for drilling the pop rivets holes. These two bays will have burner pans installed in them to enclose the bottom of the oven. not many specialty tools were needed. The first step is building the base. available from building supply houses. The studs were laid on edge and fastened with pop rivets into a frame with two bays. This pan provide support for the heating elements and prevents heat from escaping from the bottom of the oven. The two outer flanges lay on the base rails and are pop riveted for fastening.Constructruction Page Each bay of the base has a burner pan as the floor. . This picture shows a burner pan installed in one of the bays and the heating element being installed. The panels are made of 28 gauge galvanized sheetmetal wrapped around a core of 2" rigid fiberglass insulation. All seams are fastened by pop rivets.Constructruction Page The next step is the construction of the panels that make up the shell of the oven. This picture shows placement of insulation in a panel. then fill the remaining two open ends with separate fillers. This is not the same panel as in the previous picture. Typical procedure was to bend a single piece of metal 4 times to form it into a rectangular box. This picture shows the brake making the third bend. This panel overlaps the panel adjacent to it and you can . . The drawing in the next frame will show better how the panels are constructed.adobe.Constructruction Page see the overlap protruding about 1-1/2" at the bottom of the picture. Visit www. You must have the Adobe Acrobat Reader to view this file. Here is a drawing of the oven. Click Here to view a PDF file of this drawing.com to download the Acrobat Reader for free. This panel actually requires three separate fillers to enclose the insulation. Power (110v) is routed through the ON/OFF switch and is controlled by the thermostat. All text. images.Constructruction Page The electrical panel shown here was fabricated from the same sheetmetal as the rest of the oven. This circuit activates the coil of the contactor. Two heating elements are wired together and plug into each of these receptacles. The oven has an interior light and switch which I have omitted here for clarity. The thermostat causes the contactor cycle open and close to requlate the termperature. which closes the 220v circuit that feeds the heating elements. The schematic to the left shows how the oven is wired. and drawings are Copyright 2004 by Gary Brady . The heart of the electrical system is the contactor. The two round objects on the bottom of the panel are actually 220v receptacles. Click here for a larger view with labels. Click Here to veiw a PDF file of this drawing. This allows the oven to be disassembled easily for storage. which is an electromagnetic switch. Warning: 200K file. Utility: Utility consideratons are those physical characteristics that define how the oven will be used. since it works will with frames as well as smaller items such as wheels. type of material used for construction. I'd like to collect data from your experiences. The exterior surface area will increase at a proportionately higher rate as the volume increases causing a greater heat loss for larger ovens. The trolley type racking device was also chosen. the oven heats to 450 deg in less than 10 minutes. and portability are all utiility considerations. An increase in insulation thickness would be warranted for larger ovens. The volume of this oven is 36 cubic feet. so the horizontal configuration of a rectangular box. Shape. loading from the end. please contact me. racking of items.Home Construction Page Design Page Material List Contact Links Design Considerations All data presented on this page has been collected from the construction and operation of the oven shown in this website. If you've built an similar oven. The performance related criteria here are volume of the oven. size. The oven shown in this website was intended to be used for ATV frames and smaller items. . type of insulation. was the chosen shape. This heat input factor would be valid only for an oven of this approximate size. Using a 2" rigid fiberglass insulation board for the entire enclosure except the base. This actual data indicates that a heat input of 333 watts/CF of oven volume will provide an acceptable heat up time. and heating element output. Oven design considerations are grouped into the following two general categories: Performance: Performance criteria are the physical aspects of the oven as they relate to how the oven will perform. while total exterior surface area is 72 square feet. or 12kW. objects to be baked. Each of the four elements is approximately 3000 watts for a total of 12000 watts. Professional powdercoaters would proabably want an oven that was stationery or mounted on wheels. may be more serivceable for some items to be coated. which rides in Unistrut mounted to the underside of the top.Design Page fenders. and in fact. All text. the base is quite flexible unless lying flat on a smooth concrete floor. however. that is. The fact that I own a sheetmetal brake was also a factor in the construction that I chose. there is no one right way to build an oven. The trolley requires modification from time to time to hold different items. One of my most important considerations was that the oven be portable. Clearly. the panels are the structure and are light in weight and easy to handle. and drawings are Copyright 2004 by Gary Brady. images. that it could be disassembled and stored away on a shelf in the rafters of my shop when not in use. There is no structure per se.com/Design. similar to this one. The type of material used for construction will probably be dictated by the capabilities and needs of the builder. etc. An overhead trolley. http://powdercoatoven.html (2 of 2)11/14/2004 8:08:27 AM . I chose the panelized approach for this oven.4t. This approach is not very sturdy. The thermostat . and view windows came from these ovens. The steel for the trolley and rails had already been purchased. Another oven was picked up (literally) from the side of the road. including one kitchen oven (I'm a remodeling contractor and frequently haul old appliances to the dump). This contactor has a 50amp capacity with a 110v coil.Home Construction Page Design Page Material List Contact Links Material List The following spreadsheet is a list of items I purchased for the construction of the oven. A number of items were already in my scrap bin. The contactor was purchased from an air conditioning supply house. .heating elements. is very similar to the contactor found in the condenser unit of many home A/C units. and was left over from a prior project.and in fact. Material List . . (Res. Amps 240-600V) .24 Sale price: $27.90 Order .50 L37-844 Regular price: $162. SPECIFICATION COMPLIANCE In U. 4. 4.25. and cavity walls.6.Type IB (3.0 PCF) http://www. wall and roof panel systems. Noise Reduction ● Excellent acoustical properties effectively reduce noise.Type IA (1. 3. APPLICATION Knauf Insulation Board is a versatile product for thermal and acoustical applications such as: heating and airconditioning ducts. boiler and stack installations. PSK facing) HH-I-558C . Type I (ASJ facing). Appearance ● FSK. 4.0 PCF) .: ● ● ● ● ● ● ASTM C 612 . It is available plain. curtain wall assemblies. Low-Cost Installation ● ● Lightweight.Printer Friendly Page KNAUF INSULATION BOARD DESCRIPTION Knauf Insulation Board is a thermal and acoustical insulation product made from inorganic glass fibers preformed into boards bonded by a thermosetting resin. 6.Type II. 3.25.S. 6. easy to handle and fabricate. PSK) California Title 24 HH-B-100B.Form A.knauffiberglass. Class 1 (1. easy installation lowers labor costs. 2.25. IV (FSK. Fast. 6.25. PSK and ASJ vapor-retardant facings provide a neat finished appearance. IV (ASJ) .0.cfm?fuseaction=prd.com/index. metal and masonry walls. power and process equipment. with a factory-applied FSK facing or PSK (metalized polypropylene-scrim-kraft) facing.dspProdDetail&ID=12 (1 of 7)11/14/2004 8:10:21 AM . FEATURES AND BENEFITS Energy Conservation ● Excellent thermal efficiency results in lower operating costs.0.0.6. II.25. III.0 PCF) ASTM C 795 ASTM C 1136 (facings) . 2.Type I. or with a factory-applied all-service jacket (ASJ). Type II (FSK. If natural convection is not adequate in confined areas. PSK Facing: 25 ASJ Facing: 50 Water Vapor Transmission (ASTM E 96.36 In Canada: ● ● ● CAN 4-S102 CGSB 51-GP-10M CGSB 51-GP-52M (facings) TECHNICAL DATA Surface Burning Characteristics (UL Classified) ● Does not exceed 25 Flame Spread. Procedure A) ● FSK. Water Vapor Sorption (ASTM C 1104) ● Less than 5% by weight when exposed to air at 120°F (49°C) and 95% relative humidity for 96 hours. Guide 1.● ● ● . .0. Puncture Resistance (TAPPI Test T803) (Beach Units) ● ● FSK. Mold Growth (ASTM C 1338) ● No growth. CAN 4-S102.3% linear shrinkage. Meets the stress corrosion requirements of ASTM C 795. Shrinkage (ASTM C 356) ● Less than 0. and UL 723.02 perms.36. a slight odor and some smoke may be given off as a portion of the bonding material used in the insulation begins to undergo a controlled decomposition. 6.25. NFPA 255. Corrosiveness (ASTM C 665) ● ● Will not accelerate corrosion of aluminum.0 PCF) MIL-I-24244C NFPA 90A and 90B NRC Reg. forced ventilation should be provided in order to protect against any harmful fumes and vapors that might be generated. APPLICATION AND SPECIFICATION GUIDELINES Precautions ● ● During initial heat-up to operating temperatures above 350°F (177°C). PSK and ASJ vapor retarders have a maximum vapor permeance of . Temperature Range (ASTM C 411) ● Operating temperatures from 0°F to 450°F (-18°C to 232°C). 50 Smoke Developed when tested in accordance with ASTM E 84. Class 2 (3. MIL-I-24244C. or copper. and NRC 1. 4. steel.Form A. all penetrations and facing damage shall be repaired with tapes or mastic with a minimum of 2" (51 mm) overlap. mechanical fasteners. . Apply jacketing. VESSELS. A disposable mask designed for nuisance type dusts should be used where sensitivity to dust and airborne particles may cause irritation to the nose and throat. Use on ducts. tanks. or mastic. Tapes should be applied using a sealing tool and moving pressure. References to numerical flame spread ratings are not intended to reflect hazards presented by these or any other materials under actual fire conditions. Metal ducts must be sealed before application. the tape must be firmly rubbed with a proper sealing tool to make sure the closure is secure. loose-fitting clothing. Cartons are not designed for outside storage. Insulation can be secured with adhesive. DUCTS AND PLENUMS: Use 3.6 pcf (26 kg/m3) insulation board and band with minimum compression. Insulation Board is not designed to be exposed to the airstream. Use 6. Follow tape manufacturer's recommendations. mastics. Vapor retarders should overlap a minimum of 2" (51 mm) at all seams and be sealed with appropriate pressure-sensitive tape. AND EQUIPMENT: For irregular surfaces. vessels. dry surfaces. Tapes and mastics (dry) should have a UL 723 rating of 25 Flame Spread. TANKS. For outdoor applications. 50 Smoke Developed.0 pcf (48 kg/m3) insulation board in concealed areas. All exposed surfaces must be protected.Storage ● Protect material from water damage or other abuse. Wash with soap and warm water after handling. and equipment operating at temperatures of 450°F (232°C) or less.0 pcf (96 kg/m3) insulation board in exposed areas. or other vapor retarder. Prescore rigid insulation board where necessary to conform to curved surfaces. Minimum compression is to be used to assure firm fit and still maintain thermal performance. gloves. NOTES The chemical and physical properties of Knauf Insulation Board represent typical average values determined in accordance with accepted test methods. mastic. Wash work clothes separately and rinse washer. Wear long-sleeved. plenums. use 1. and other vapor retarders in accordance with manufacturer's instructions. Knauf Insulation Board must be covered with appropriate jacketing. The data is supplied as a technical service and is subject to change without notice. Preparation ● Apply the product on clean. Vacuum packaged material can be stored outside if care is taken not to puncture the polybag. Where vapor retarder performance is necessary. Application GENERAL: All insulation joints must be firmly butted. or banded. and eye protection when handling and applying material. head covering. Fasteners shall be located a maximum of 3" (76 mm) from each edge and spaced no greater than 12" (305 mm) on center. Check with your Knauf regional office to assure information is current. When applying pressure-sensitive tapes. ● ● ● ● ● ● ● ● ● ● ● ● Caution Fiber glass may cause temporary skin irritation. The data is subject to normal manufacturing variations. 28 .81 1.23 .23 .55 .035 .THERMAL EFFICIENCY (ASTM C 177) Mean Temperature 75°F 100°F 200°F 300°F 1.75 .039 .04 1.033 .04 .22 .24 .12 1.44 .24 .00 .31 .043 .033 .061 .29 .98 1.63 .035 .050 .05 .90 1.96 1.035 .00 1.06 .6 PCF (26 kg/m3) 1.6 PCF (26 kg/m3) 1.24 .85 1.82 .05 .25 PCF 3.05 .86 .89 1.75 .49 .0 PCF (48 kg/m3) 3.97 1.033 .75 .11 .85 .01 1.59 .27 .0 PCF k k k k k .0 PCF (48 kg/m3) 3.43 .0 PCF 4.34 THERMAL EFFICIENCY (SI) (ASTM C 177) 1.0 PCF (48 kg/m3) Facing Thickness 125 Hz 250 Hz 500 Hz 1000 Hz 2000 Hz 4000 Hz NRC Plain Plain Plain Plain Plain Plain Plain FSK FSK Plain Plain Plain 11/2" (38 mm) 2" (51 mm) 21/2" (64 mm) 3" (76 mm) 1" (25 mm) 11/2" (38 mm) 2" (51 mm) 1" (25 mm) 2" (51 mm) 1" (25 mm) 11/2" (38 mm) 2" (51 mm) .00 1.24 .032 .26 .22 .03 .65 .62 .25 PCF 6.09 .88 1.033 .05 .040 .39 .35 .03 1.93 1.95 .048 .25 PCF (36 kg/m3) 2.03 1.03 1.25 PCF 3.42 .86 1.04 1.0 PCF 4.11 .07 .17 .25 .06 .08 .07 1.06 1.035 . TYPE A MOUNTING) Type 1.14 .13 1.23 .37 .042 .25 PCF (36 kg/m3) 3.25 PCF (36 kg/m3) 2.65 .17 .38 .33 .6 PCF (26 kg/m3) 2. 1/3 OCTAVE BANDS (ASTM C 423.03 1.62 .04 1.6 PCF 2.25 PCF (36 kg/m3) 2.23 .96 1.00 .03 1.99 .65 .80 .25 PCF (36 kg/m3) 2.30 .27 .055 .25 PCF 6.0 PCF Mean Temperature (26 kg/m3) (36 kg/m3) (48 kg/m3) (68 kg/m3) (96 kg/m3) k k k k k 24°C 38°C 93°C 149°C .19 .69 .24 .99 1.47 .57 .42 .02 1.053 .29 .03 1.99 1.6 PCF (26 kg/m3) 1.06 1.049 SOUND ABSORPTION COEFFICIENTS.76 .6 PCF 2.036 .23 .92 . 00 .07 .55 .47 .65 .04 1.93 .26 .62 1.77 .3 8.54 .78 .6 PCF (26 kg/m3) 1.03 .42 .47 .70 .41 .08 .32 .07 1.24 .80 .07 .40 .41 1.75 .25 PCF (68 kg/m3) 6.06 .77 1.75 .74 .65 .25 1.04 1.0 PCF (96 kg/m3) 6.65 .46 .05 1.07 1.25 PCF (68 kg/m3) 4.84 .0 PCF (48 kg/m3) 3.63 .91 .58 .32 .77 .63 .01 1.51 .0 PCF (96 kg/m3) Plain Plain FSK FSK FSK ASJ ASJ ASJ Plain ASJ Plain Plain Plain FSK FSK FSK ASJ ASJ 3" (76 mm) 4" (102 mm) 1" (25 mm) 11/2" (38 mm) 2" (51 mm) 1" (25 mm) 11/2" (38 mm) 2" (51 mm) 1" (25 mm) 21/2" (64 mm) 1" (25 mm) 11/2" (38 mm) 2" (51 mm) 1" (25 mm) 11/2" (38 mm) 2" (51 mm) 11/2" (38 mm) 2" (51 mm) .23 .01 1.0 PCF (48 kg/m3) 3.50 .0 PCF (96 kg/m3) 6.69 .65 .6 PCF (26 kg/m3) 1.90 1.71 .30 1.2 .41 1.75 .60 .75 .23 .15 .3 10.53 .05 .0 PCF (48 kg/m3) 4.60 .67 .48 .05 .41 .10 .95 .63 .02 .39 .65 .06 .60 .60 1.13 .48 .24 1.0 PCF (48 kg/m3) 3.00 1.61 .4 12.0 PCF (96 kg/m3) 6.47 .6 PCF (26 kg/m3) Thickness R-Value R-Value (SI) 11/2" (38 mm) 2" (51 mm) 21/2" (64 mm) 3" (76 mm) 6.27 .69 .16 .93 .17 .04 .72 .60 .01 1.28 .58 .1 1.18 1.99 .0 PCF (48 kg/m3) 3.8 2.0 PCF (48 kg/m3) 3.41 1.0 PCF (48 kg/m3) 3.66 .47 .6 PCF (26 kg/m3) 1.3.50 FORMS AVAILABLE* Density 1.80 .0 PCF (96 kg/m3) 6.81 .5 1.75 .82 .62 .21 .53 .11 .04 1.0 PCF (96 kg/m3) 6.44 1.45 .55 .50 .0 PCF (48 kg/m3) 3.73 .31 .06 .77 1.61 .99 .71 .03 1.22 .51 .50 1.0 PCF (96 kg/m3) 6.10 1.50 .35 .0 PCF (96 kg/m3) 6.5 1. 9 13.1 1.6 PCF (26 kg/m3) 1.2 17.0 PCF (48 kg/m3) 4.9 4.25 PCF (36 kg/m3) 2.6 6.7 10.7 8.4 4.5 8.6 PCF (26 kg/m3) 2.5 8. .0 PCF (48 kg/m3) 3.25 PCF (68 kg/m3) 4.8 1.9 13.5 1.8 1.1 1.1 .1.25 PCF (36 kg/m3) 2.7 10.4 4.5 1.25 PCF (36 kg/m3) 3.25 PCF (68 kg/m3) 4.6 16.8 1.25 PCF (36 kg/m3) 2.7 4.2 17.1 1.9 .1 .5 1.5 8.0 PCF (48 kg/m3) 3.0 PCF (48 kg/m3) 3.9 .3 2.7 3.0 15.3 6.9 2.7 10.6 2.0 PCF (96 kg/m3) 6.3 6.0 PCF (48 kg/m3) 3.0 PCF (48 kg/m3) 3.25 PCF (68 kg/m3) 4.0 PCF (96 kg/m3) 6.2 1.0 PCF (48 kg/m3) 3.0 PCF (96 kg/m3) *Available in widths of 24" (610 mm) and 48" (1219 mm). Available in lengths from 36" to 120" (915 mm to 3048 mm).3 6.25 PCF (36 kg/m3) 2.25 PCF (68 kg/m3) Privacy Policy Terms of Use 31/2" (89 mm) 4" (102 mm) 1" (25 mm) 11/2" (38 mm) 2" (51 mm) 21/2" (64 mm) 3" (76 mm) 31/2" (89 mm) 4" (102 mm) 1" (25 mm) 11/2" (38 mm) 2" (51 mm) 21/2" (64 mm) 3" (76 mm) 31/2" (89 mm) 4" (102 mm) 1" (25 mm) 11/2" (38 mm) 2" (51 mm) 21/2" (64 mm) 1" (25 mm) 11/2" (38 mm) 2" (51 mm) 14.25 PCF (36 kg/m3) 2.4 6.9 2.3 2.8 1.0 15.7 3.25 PCF (36 kg/m3) 2.9 2.