Marking Parts

The purpose of marking parts is to be able to find it and place it in an assembly where it’s supposed to go. Using inferior marking methods will lead to erased labels and misplaced parts. Our builders sent in these tips to help you get on the right track.

sharpieFlange marker lines: This is a tip I’m passing on from a fellow GlaStar builder in Largo, Al Werly. If you are having trouble spotting your Sharpie marker lines when fitting a drilling ribs, spars, and skins, try using 1/16″, day-glo orange, chart marking tape, available from some office supply stores.

–Phil Frasier

Identifying and marking various parts:
for subsequent re-assembly is a key requirement during construction of the GlaStar. An essential requirement for the marking system is that it has to survive handling, chemicals (including degreasers, acid etching and alodine baths, and so on), and priming. It has to be robust to stay intact and attached to the part, and remain readable after all that, all the way up to point where the parts are re-assembled just before riveting. In a forum discussion, several marking solutions were identified including coded scratches and/or punches, and engraving. Stoddard-Hamilton does not recommend any of those solutions, however, because of the potential for stress cracking of the metal. SHAI does recommend marking the parts with attached tags. Finding a tag, however, that can live through the metal prep process leading up to the final assembly and riveting stage and remain attached and readable took some effort. What I came up with works, it’s easy, and it doesn’t stress the parts. I found an Avery Item No. 11-203 “Self Laminating Tag” (1-3/8″ x 2-3/4″) and an Avery Item No. 11-055 “Secur-A-Tach” polyethylene fastener. You write on the tag, peel away a protective paper on the laminate overlay, and seal the tag with the self-sticking laminate. You attach the tag to the part using the fastener which is a thin, tough, 5″ strand of poly with a locking arrow and socket at the ends. The mylar reinforcement of the tag resists pulling-out of the fastener. Although liquids do penetrate into the side of the tag, it stays together and readable after immersion in water, MEK, MEK peroxide, acetone, methyl and ethyl alcohol, trichloroethane (electronics degreaser), toluene, “metal prep”, and alodine solution. I tried using pencil, ballpoint-, felt tip-, fountain-, and Sharpie-pens to mark on the paper before “sealing” the laminate. All of the writing tools worked fine, except for the ballpoint — it smeared under the laminate when it got wet. (Note: if a label is pressed against a part after the acid bath, for example, the acid could get squeezed out onto the part and leave some residual acid on the part(s). Not good. For this reason, one should keep the parts separated after the acid and alodine baths) If your local office supply doesn’t carry these Avery items, or won’t get them for you, you can order them from MBA Office Supply in San Jose, CA. Order MBA Cat No. AVE-11-055 for the fasteners (100/pack @ $3.29/pack) and AVE-11-203 for the tags (50/pack @ $8.10/pack)


–Dennis Douglas

More on marking parts:
Dennis noted the potential use of Avery”Self Laminating Tags” or Avery “Secur-A-Tach” polyethylene fasteners for parts identification. Both sound good. I have another suggestion. In my local “we-have-everything” hardware store, I found metal tags with copper “strings” used to identify steel traps, etc. The tags are very thin, and mark quite easily with metal punches (R1, R2, L1, L2, etc.). They are large enough for a fair amount of information, although I keep mine brief (quicker). I’ve been able to recycle them (horizontal stabilizer, then elevator, then ailerons – flaps next) because I use a universal marking scheme as above. I remove the tags as I assemble to rivet and put them on the next component. If you can’t find the tags at your local hardware store, send me an e-mail and I’ll get the manufacturers’s address. They come 50 to a packet including the copper strings. They do break from time to time (wear and tear) but I just punch a new hole and use the broken pieces. They’re impervious to anything except bending.

–Joe Colquitt

Torquing nuts: Put a color paint bar on all lock nuts immediately after they are torqued to ensure that they have been torqued and to check for any slippage.

–Jim Londo

Marking Parts: Mark your parts using tie-wraps. Buy plastic tie-wraps in as many colors as you can find (at least 10). Develop (and record!) a system where (for example) red=1, orange=2, yellow=3, etc., and black=0. (We found some fluorescent orange, pink and green tie wraps to round out our selection.) When you’re ready to mark parts, figure out a logical sequence of numbers to use for the parts that need to be marked, and write the numbers into a figure in your instruction book that shows the parts. For example, we numbered our wing ribs from inboard to outboard, using separate sequences for the main ribs (1-6), flap cove ribs (1-??) and aileron cove ribs (1-??). To mark parts, simply loop the appropriate tie wrap through an index or lightening hole. The loops are also useful for hanging up primed parts to dry. A tip for advanced uses of this system: If you have more than 10 of the same thing (or left and right versions of the same thing), you can cut off the tail end of the tie wrap differently (e.g. straight cut or on the diagonal), to differentiate between left and right, or to number things from 11 through 20. Use your imagination! Just be sure to WRITE DOWN what you did.

–Kathy Sutton

Another way to mark parts:
With so many creative ways disclosed to mark parts, I still just ended up grabbing something handy and using it. To tag a part for cleaning and painting I attach a tag made from aluminum foil. I attach it with simple aluminum wire from a hardware store to avoid using a dissimilar metal or scratches from a harder wire. To make the tag, fold a piece of foil several times to finally end up with a tag about 1 by 3″ with 8 to 10 thicknesses of foil in the tag. Use a paper punch to make a hole in one end. Loop a piece of aluminum wire through the hole to prepare the tag. To mark a number, just peel back the top fold, write the number inside with a ballpoint pen, press hard enough to physically mark the number in the foil. The pressure is about the same as writing. Fold it closed and attach. After all the work is finished, the inside of the tag is still fine and the number is pressed into about 6 or 8 layers of the foil, the ink from the pen doesn’t have to be there. Hang the parts for drying or painting with the tags at the bottom in case some water is trapped inside the folds. This works very well and is dirt cheap.

–Michael Harfst

Throw away that Sharpie!:
Throw away that “Sharpie” and that “eyeball method” described in Section II: Tools and Techniques. I have found that that stupid little Edge Marker from Avery ($7.50) and a RED Fine Point DecoColor Opaque Paint Marker from an art supply store (Aaron Brothers Art Mart – $2.00) which fits it exactly, is by far the best rib- marking method. I sure beat my tape, Sharpie, and tri-square method. I even beat a couple of other marker tools I have seen (some homemade). Sharpies rub off too easily, and the red Sharpie is weak compared to the DecoColor. This marker leaves a VERY BRIGHT RED mark that is almost the same size as the pre-punched holes. It alleviates all doubt about being on a black line or a shadow when viewed through the skins. It also lets me know when I am right on the mark or close enough to specification (2D-minimum ED). Usually if I can just see red, I am at the limit but good enough for all 3/32 rivets. Take care with 1/8″ rivets since there is minimal room on the rib flanges. Spar lines are straight, unwavering as are made with clumsy homemade varieties of Sharpie penholders.

In marking RIBS, make sure that the rib flanges are on the same level if they are near the same width. This is especially important on ribs that have flanges with pre-punched pilot holes. THE SPAR PRE-PUNCHED PILOT HOLES SPACING MATCH THE SKIN PRE-PUNCHED PILOT HOLE SPACING. The transfer of this alignment must occur and meet on the marked centerlines on the ribs. Note that some rib flanges seem a little long or short (1/16″). This is a result of the flat blank size, bent radii at the flanges, form tooling locator variation and the forming process. It seems though that all parts are consistent in general. Some variation may also occur when the packaging people that box up your kit, smash the ribs together to keep the packaging size (and shipping costs) down. After I pry apart the ribs, take the bow out of the webs and square up the flanges, I then set the ribs on a flat hardwood block, flange- edge down. I use another wood block and small hammer and tap lightly to bring the flange edges on the same plane. I then re-check and straighten the bibs for bow and square. I then mark the ribs flanges in-line with the pre-punched pilot holes, if any.

I set the Avery Edge Marker with the DecoColor Marker up on the pre-punched flange pilot holes centers. I set the Edge Marker against the web side of the rib flange. That way I am assured the mark will always be the same distance from the formed flange regardless of the flange width variations. I then use that setting all around flanges of the same width. Keeping the marks as close to center and in-line with pre-punched pilot holes can ensure that alignments will be as good and minimize bad EDs, rivets falling close to the formed radius and less repair/replacement later in assembly.

After everything is drilled, the DecoColor is easily removed with a paper towel and Acetone.

–Gus Gustavson

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