Heater box

The main fields of application of particulate filled polymers is shown in Figure 2. As was mentioned earlier, the major benefit of the application of fillers and reinforcement is increased stiffness and HDT. Specific applications which must be mentioned here are garden furniture (CaC03), air-filter covers, heater boxes (talc) for cars, washing machine soap dispensers (talc), etc. Bumpers are usually made from multi-component PP systems containing a PP homo- or copolymer, an elastomer and a filler. In order to demonstrate the usual property range of particulate filled polymers. Table 1 presents the most important characteristics of several commercial grade PP composites. 

B Homopolymer + 40% talc Heater boxes, instrument baeks. parcel tray supports... 

In reality, the heater box was short of air. The unburnt hydrocarbons completed combustion upon mixing with the air drawn into the convective section. The liberation of radiant heat in the midst of the convective tube bank oxidized the steel alloy fins on the tubes. R. D. Reed has discussed this subject in detail. ... 

The main applications of calcium carbonate filled PP are in instrument panels, motor vehicle grills, heater boxes and garden furniture. 

The heater box is made from 20 gauge h.r.s. sheet metal. It is made in sections and then riveted together with 1/8 pop rivets. You probably do not have a sheet metal brake so an alternative method of making the bends is with a sheet metal tool. The photo in figure 102 shows what a sheet metal tool looks like. It s really just a pair of vise grips with wide flat jaws. If you are careful and make the bends gradually you will end up with a professional looking bend. 

Figure 103 Sde panels for the heater box. Make 2 from 20 gauge h.r.s sheet metal.

Make the hinge frame next from a 44 long piece of 1/8 x 1-1/4 h.r.s. strap iron. Locate and drill the 1/4" holes as shown in figure 109. The two 3/4 holes shown in the drawing will be located and drilled later to match the holes in the heater box. 

Next, mount the hinge frame to the heater box as shown in flgure 113. Center the hinge frame on the side of the heater box. Clamp the frame in position. Use the 1/4 holes in the frame as a template for drilling 1/4 holes in the heater box. Then bolt the frame to the heater box with 1/4-20 x 1/2 bolts with nuts. 

Make sure there is plenty of clearance through the 3/4" holes for the heating element because you don t want the bare leads of the element to touch the box. If this were to happen it would cause an electrical short. If necessary enlarge the 3/4" holes to give additional clearance. Mount the front bracket to the heater box using the existing holes in the bracket as a template to drill through the heater box. Attach the bracket to the box with a couple of 8-32 X 1/2 machine screws and nuts. 

To fasten the element bracket, insert the spacer blocks between the bracket and the heater box then fasten with 8-32 x 1 machine screws nuts. 

Place the heater box in position on the hinge pin as shown in figure 116. You will notice that the box has a tendency to sag at the right front corner. To solve this problem make the cross brace... 

The heater delivers radiant heat to the plastic sheet. Radiant heal works much better when it has a shiny surface to reflect off of. To improve performance, I painted the inside of my heater box with high temperature spray paint. Important Use only high temperature paint I used an Ace Brand, shiny aluminum color. Hi Temp paint. This type of paint is available under several other brand names. It was purchased at the local Ace hardware and it was rated for temperatures up to 1000 degrees F. 1 painted the outside of the heater box with the same paint to protect the finish from rust. 

First we will run the male power plug to the heater box. The... 

Figure 129 The drawing shows the wiring from the outlet to the control panel and then to the heater box. In this representation we are using a Robertshaw 5500-135 infinite range switch. Please note The wiring could be different than that shown, depending on the components you use. Always follow manufactures instructions as well as all local codes for all of your wiring.

Use extreme caution around the heater box Its outside surface reaches high temperatures capable of causing burns. Treat it like you would any oven. Use the handle when moving the heater from side to side, and as an added protection, wear gloves. 

Eight 1/4-20 X 1/2 bolts with nuts. For mounting the hinge frame to the heater box. See figure 113. 

Two 8-32 X 1 machine screws with nuts. For attaching heating element to heater box. See figure 115. 

Assemble the sides and ends of the heater box as shown in figure 105. Drill holes for the 1/8" x 1/4 pop rivets in the approximate locations shown. Don t rivet the seams within 1" of the bottom because that would interfere with the installation of the top. 

Cut out the top panel of the heater box from 20 gauge h.r.s. sheet metal. Entails are given in figure 106. Bend the edges up at 90 degrees. 

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