The accompanying illustration. Fig. hi, shows a concrete bench which is especially designed with a view of meeting the demand for a simple yet artistic piece of lawn furniture, and at the same time can be made with a minimum amount of skill and expense by those who are as yet uninitiated in this work. A detail drawing of the
end supports or the bench pedestals is shown ir. Fig. 112, and details of each piece used in the making of the wood mold for these end supports are shown in Fig. 113. The assembled mold ready for placing the concrete is shown in Figs. 115 and 116.
The lirst thing to do is to procure a l-inch board, 12 inches wide by 16 inches long, and cut it to the shape shown in Fig. 113 at A. This is to be used for the bottom of the mold, as shown in Fig. 115. Now cut another piece of board, also i-inch thick, shaped as shown in Fig. 113 at R, and nail ;t down :n its proper position on piece A.
Fig. 112—Detail of Bench Pedestal
Fig. 112—Detail of Bench Pedestal
The next piece to make is piece C in Fig. 113. l'his piece forms the recessed panel; this panel as shown in Fig. 1121s only ^ inch deep, therefore this piece should be made of ^-inch board. Nail this securely in position, as shown in Fig. 115 on piece B. Be sure to he\ el the edges of pieces B and C, as shown by the dotted lines in Fig. 115, for if this is not done, one will have trouble in releasing the mold from the concrete when it is set or hardened. Xow proceed to make the pieces I), E, F, G, 11, 7, /, K, 7-, and M all of r-inch thick material, care being taken to follow the dimensions given closely. When these pieces are
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Fig. 113—Details of Mold for Bench Pedesta_
Fig. 113—Details of Mold for Bench Pedesta_
all made, assemble them as shown in Fig. 11;, using as few nails as possible in securing the pieces to one another; for when the concrete is hardened, the form or mold will have to be removed from it, and the fewer the nails used, the easier the form can be stripped from the cast. In making the form use green or unseasoned wood, as it is less liable to warp when the wet concrete mixture comes in contact with it. Before assembling the mold, each piece should be shellacked thoroughly
on both sides as well as on the ends. This will in a great measure prevent the mold from absorb ing moisture, and will thus prevent any tendency of the mold to warp or buckle. After having assembled the pieces, as shown in Figs. 115 and 116, if for any reason the joints do not match up as well as they might, they can be filled with putty or piaster of Paris, care being taken however to have everything square and true.
After having trued the mold up, the inside of it should again be shellacked, and when thoroughly dry, a thin coat of fairly thick oil should be given to all parts of the mold which will come in contact with the wet concrete. The mold is now ready to be rilled with the concrete mixture^ which should be composed of 1 part Portland cement, 2 parts of good clean sharp sand, and 2 parts of trap rock or pebbles ranging in size from % inch to inch. The method of mixing the concrete is as follows: It is important to follow the directions closely, for if the concrete is not properly mixed, an inferior product will be the result. First the sand should be evenly spread on a level water-tight platform. The cement should then be spread upon the sand. Then, after thoroughly mixing the cement and sand together until it is of a uniform color, water should be added, preferably by spraying, and the mass thoroughly turned over and over by means of a shovel or hoe until it is of a uniform consistency of a fairly-thick putty. To this mortar should be added the stone or gravel, which has previously been drenched with water, and the whole mass should then be mixed or turned over unti' the aggregate or stone is thoroughly coated with mortar. An ordinary garden rake is a good tool with which to distribute the stones through the mortar, as it distributes them more uniformly than a shovel.
The concrete thus mixed should be deposited in the form or mold as soon after mixing as possible. Under no conditions deposit concrete in molds which has been mixed more than two hours. To rill the mold use a shovel, care being taken to
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Fig. 115—Assembled Mold for Bench Pedestal
Fig. 115—Assembled Mold for Bench Pedestal deposit the concrete into all of the corners. Tamp or tap it down well with the end of a piece of board. If the concrete has been properly mixed, this tamping will bring to the surface of the mass a slight skim of water. The mold should first be about half tilled, and then a strip of Clinton wire cloth or other steel reinforcing fabric should be placed in the form, as shown by the dotted lines in the plan view of the assembled mold in Fig. iii. The proper size of wire cloth to use is that known as 3-inch by 12-inch mesh, made of Nos. 8 ar.d 10 gage steel wire. If wire cloth is
not available, any good No. 8 gage steel wire, cut and placed as shown, will answer the purpose. After having placed the reinforcing, continue to deposit the concrete, and tamp it down until it is level with the top of the sides I) and E of the mold. Scrape or float this surface level, and then take the cross strips L and M, shown in Fig. 11.3, and secure them to the top of the mold and against the end pieces II I and J K, as shown by the dotted lines in the side elevation in Fig. 11?. These cross pieces not only act as a form for the edges a and b of the pedestal, as shown in Fig. 112, but they also act as a brace to the sides of the form, and prevent them from spreading apart.
due to the weight of the plastic concrete pushing against them.
After having secured these pieces ;n place, fiH the portion of the mold thus formed flush with the top of the strips and the end pieces G and h. Tamp the concrete down, and smooth the surface off nicely. The filling of the mold is now com plete, and it should not be disturbed for at least twenty-four hours, after which the cement should be wet down occasionally with a spray for at least a day. After having set or hardened for two days, the cast can be removed from the mold, and can be set aside to be cured or to harden up. This is done by sprinkling it with water two or three times a day for at least seven to ten days. Care should be taken when removing the mold not to injure it or the cast, as the mold if not broken can be used over and o\ er again. In removing the mold from the cast, first detach the cross strips 7, and M, then the pieces 77, 7, J, and K, then the end pieces F and G, next the side pieces E and D, and then the bottom piece, composed of pieces A, R, and C. Before using the mold again, it should be thoroughly cleaned of any particles of cement which may have adhered to it. After having cleaned it well, oil the inside and proceed to assemble it as before, and cast the other pedestal for the bench in a similar manner as explained above.
The next step is to cast the slab or seat of the bench. This is 5 feet long by 18 inches wide by 3 inches thick. The form or mold for this is nothing more or less than an oblong box, having a bottom £ feet long by 18 inches wide and four sides each 3 inches high, as shown in Fig. 118. The bench scat should be reinforced with the same size of wire cloth as was used in the pedestals, or by three j4-inch round rods spaced 6 inches apart. The reinforcing steel should extend within 3 inches of all four sides, and should be placed about inch from the under surface of the slab, as shown in Fig. 118.
It would be well to clearly mark the under surface of the slab, so as to know which surface the reinforcing is nearest to, after the slab is cast, as it is 'mportant when placing the slab on the pedes-
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Detail of Bench Top *r Stat Sh'ftH-f ftemfercti+p.Qnd Detail0/ Mbutit -
Fig. 118—Details of Bench Slab or Seat Showing Reinforcing and Mold for Same tals to always have the reinforcing nearest the underside of the seat. Shellac and oil the inside of the mold, and proceed to fill it with a mixture composed of the same material as was used for the pedestals. First fill the mold to a depth of y2 inch, and then lay in the reinforcing as indicated in Fig. 118, and on top of this place the remaining
2J-2 inches of concrete and tamp it down well. This top surface will be the top of the finished bench seat, therefore it will pay to take pains in finishing it to as smooth a surface as one can. Cure or harden the slab in the same manner as described for curing the pedestals. It is well, however, not to attempt to remove the under part of the mold for at least from seven to ten days. The sides of the form can be removed any time after forty-eight hours.
A good smooth surface can be given to the hench by wett'ng it down well and rubbing it with a fairly fine grade of carborundum brick. By tooling the recessed panel in the outer sides of the pedestals by means of gently striking the surface with a chisel and hammer, a good stony effect will be produced, which will greatly add to the appearance of the ends.
If on taking off the mold the cast should in any way be injured, the damaged parts can readily he replaced or filled in by applying and form'ng into shape cement mortar composed of I part cement to i or 2 parts of sand. Before applying this mortar, be sure to wet down the surface of the cast thoroughly, for if not, trouble will be had in securing a good and permanent bond. In setting the bench up, place the pedestals about 7 inches in from the ends of the slab, as shown ir. the illustration.
It is unnecessary to secure the slab to the pedestals in any way, as its weight will keep it in place. If one should wish the top edges of the slab beveled off, a triangular strip of wood can be secured along the bottom edges of the mold, as shown in the cross section of the slab mold in Fig. 118.
15y following along the same general directions as given for making the bench shown in Fig. 111, one may elaborate on the design of the bench ped-
Fig. 119—Design for Bench Pedestal with Curved Outline ard Mold for Same estais. For instance, in Fig. 119 is shown a pedestal having curved outlines. 7'he mold for this is made similar to the mold shown in Fig. 115, with •■he exception of the sides. A simple way to make a form for a design of this kind ;s to use sheet tip or thin galvanized iron, as shown in Fig. 119. If one has not the facilities for cuttincr and bend-
Fig. 119—Design for Bench Pedestal with Curved Outline ard Mold for Same
Ing the tin to shape, any tinsmith will ilo it for a trilling cost. All that is necessary to do in this case is to furnish the tinsmith with a lull-sized drawing of the outline required and the width of the t!n of which to make it. This width w'll be the same as the depth of the mold, and in no case need the depth of the mold be more than 7 inches. It :s always well to brace these tin sides of the mold by means of strips of wood, as shown in Fig. 119. This will prevent them from bulging when the concrete mixture is placed in the mold.
Some very interesting surface cftects can he obtained in the pedestals by using selected aggregates or stones. When using this method, the concrete is mixed exactly as previously explained, with the exception that instead of using plain pebbles or trap rock, one should use trap rock and white marble or broken-up red brick. The size of the pieces used should not exceed Yz inch to J4 inch. Place the mixture in the mold as previously explained, but instead of allowing it to remain there for two days as before, remove the forms in from eighteen hours to twenty-four hours. The concrete will then be found a little soft. By spraying the cast with water and gently brushing the surface with a good stiff brush, the surface cement will be removed, and the stone and marble and pieces of red brick will gradually be exposed, thus producing a surface more or less resembling mosaic. The possibilities of the effects which can be obtained with this treatment, as pre viously explained, are only limited by the colors and size of the stone aggregates which are availa ble for use. If any surface cement should remain on the stones or exposed aggregate after the above treatment, a solution composed of 1 part commercial muriatic acid to 4 parts of water can be applied to the surface of the cast by means of a
Fig 120—Ornate Concrete Bench—Executed by the Frkins Studifv brush. This solution should be allowed to remain on the surface for from fifteen to twenty minutes. Then the surface should be thoroughly cleaned off by means of washing with good clean water and a stiff brush. This acid treatment will cut away all surplus cement and will leave all of the stones clean and bright, thus producing a surface full of life and sparkle.
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