The operation of marking out the timbers of the frame by means of patterns or molds furnished from the loft is called "molding." It is a highly specialized operation, requiring some knowledge of lofting and a systematic and methodical procedure. The molder must not only keep an accurate record of each timber molded, and of the number of timbers to the frame, but must be able to utilize the ordered flitch to the best advantage and with the least possible waste.

There are two general schemes of building molds for frames. The first is to have three molds for each frame, a floor mold, one mold from the floor to and around the bilge, and the third mold thence to top of the frame. On these molds the various timbers are marked and numbered or named.

The second scheme is to have a mold for each timber of the frame. These are more convenient to handle and do not require as great skill in handling as molds built under the first scheme.

Slight variations of each of these two systems are also often used.

Complete information for the proper laying out and marking of each timber appears on the molds. Molds need not necessarily be made to full width of the timber and, in fact, are not commonly so made. The outside edge of the mold is made true to the shape of the outside of the frame, while the inside edge may be scribed off inside of the inner line of the frame as much as six or eight inches. This is done solely to reduce the width of the mold and save mold lumber. In marking out a timber from a mold so made, the outer edge and butts are scribed direct from the mold, while the inner edge is scribed by means of a distance piece from the inside of the mold, thus accomplishing the same result as if the mold were full size.

The following information is marked on each mold: First, the exact location of each butt; second, the number or name of the futtock or timber on each side of the butt; third, the bevel at frequent intervals to which the timber is to be sawn; fourth, the number of the frame to which the timber belongs; fifth, if the mold is a floor mold it will have scribed upon it the center line corresponding to the center line of the keel; sixth, if the mold falls in way of a horning point not on a butt, the point will be scribed and marked with its number; seventh, molds for the lower futtocks of half-frames and cants usually have one or two waterlines scribed on them which should be transferred to the timbers to assist in placing the frame; eighth, the various deck lines are usually scribed on the mold, landing in their way, although only the uppermost one is customarily scribed onto the top timbers or stanchions when they are molded.

Timbers are always molded on the faces that fit together when assembled in the frame, hence the bevel marked on the timbers from the mold will read from the center of the frame forward in one tier of timbers and from the center of the frame aft in the other tier, and if the lower tier carries an under bevel, the upper tier will have a standing bevel, or vice versa.

Bevels on molds for long and short arm floor frames should not be marked standing or under. Bevels on molds for single futtocks in frames having long and short floors may be marked standing or under, but if the mold covers more than a single futtock it is not so marked. The reasons for these rules will be seen in the following examples: -

Suppose that the first futtocks in Fig. 38 are being molded and that the futtock in the lower tier has an under bevel. Then after molding this futtock and marking it with under bevels the first futtock in the top tier on the other side of the frame is marked out with the mold same side up, but with the bevels marked standing. And likewise with the third futtock and long top. Hence it will be seen that from the same face of the mold or molds we may mold all of the timbers of same number and name and it is not necessary to mark all of the butts on both sides of the mold. Putting it another way, from the same face of the molds we can mold the top tier on one side of the frame and the bottom tier on the other side. Since these tiers have like numbered futtocks they need be marked only on the one side of the mold, the opposite tiers being marked on the other side. With a mold so marked it is only necessary to mold a given timber, once with the bevels marked under, and once with the bevels marked standing, provided, of course, that the bevel is not square, and no care need be taken to definitely locate the timber in a given tier. The same rule applies to the floors. The above applies to molds covering more than a single timber. If individual molds are used for each timber they would be marked only on one side, and the rules for bevels would remain the same.

For another example take the molding of the first futtocks in Fig. 39. Here the futtocks are in the same tier and both will be assumed to have an under bevel. Then from one side of the mold the futtock to the right would be molded and marked with under bevels, then the mold must be turned over and the futtock to the left molded with the same under bevels. Since the mold must be turned over for each futtock molded it is necessary to mark all futtocks in both tiers on each side of the molds. And if the mold covers more than one timber, then from the same side of the mold would be molded the first futtock on one side of the frame with an under bevel, and the second futtock on the other side of the frame and in the top tier, with a standing bevel, hence the bevels may not be marked standing or under on the mold, unless it is an individual mold for a given futtock only. It is also necessary in this style of frame for the molder to fix the tier in which the first futtock, or any timber for that matter, is located, so that he may know whether to mark it standing or under bevel.

From the above the following rules may be evolved for molding frame timbers:

(1) In frames where like timbers fall in opposite tiers, mold like timbers from same side of mold, but with opposite bevels.

(2) In frames where like timbers fall in same tier, mold like timbers from opposite side of mold, but with same bevels.