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Priming: How do you see reference marks?

txaviator

Well Known Member
As taught in my build class, and as common sense would dictate, all parts of the HS are riveted together, match-drilled, labeled and then taken apart for deburring, priming, etc.

A question just crossed my mind: how did all of you keep from 'erasing' your information noted on the pieces, with your Sharpie marker? Even during the cleaning stages, it would appear to me that the Sharpie references get wiped away, not to mention eventually getting covered up by primer. How did each of you do this? Surely someone has a tip or a special trick or two, learned along the way?

Thanks for sharing these tips with us 'newbie' builders! I know it sounds elementary, but if I were to essentially wipe away all of my reference markings, I would be doomed during re-assembly! :confused:
 
Hi Gary:

After you prep your parts for priming, you can always touch up your references on your parts.

I used Variprime for all my priming and had no problem reading my marks through the primer. Just don't pile the primer on too heavy. A light coat is all you need.



Regards,
 
Tags

I make little tags with safety wire and masking tape. Just run a short piece of wire thru a rivet hole twist it a couple times then wrap a piece of tape on the end away from the part. Fold the tape over on itself about an inch or so. It gets some primer on it so I write on both sides. Has worked well for me.
 
Gary--

Benefit from my mistake yesterday as I was doing my first prime job. Using Variprime 615/616. Using lacquer thinner to clean the parts first, which removes the sharpie pen.

Mostly I was just careful to remark the item with a sharpie after wiping it off with lacquer thinner. However, one time I got ahead of myself, had the entire left side HS ribs clean but un-remarked and I dropped them all--mixing them all up. "Oh no, how am I ever going to figure out which ones which?!"

The long and short of it was that I could tell which main and nose ribs were the most inboard ones (because the flanges were bent so much--as per plans). However, I had no clue about the other 4 main ribs and other 2 nose ribs. The good news--Van's tooling is so exact that I could use them interchangeably, even having already match-drilled them. Hopefully this will hold true once the skin goes on for the final time tomorrow. I think it will, or that at least it won't be too difficult to pull them into alignment with clecos before I rivet!

Moral of the story--make sure that when you wipe off the market with the cleaner that you have a "foolproof" method for gettting them re-marked once the lacquer thinner dries (which is very quick.)

Steve
(and yes, by number, I'm right ahead of you--#91132)
 
By the way, sharpie does bleed through Variprime very easily. In fact, next time I'm going to make smaller, less obvious references with the sharpie. It's kind of ugly when it bleeds through. (Course, since I'll never see those marks except on inspection, I guess it probably doesn't matter!)

Steve

P.S. If you haven't got to the rudder horn brace yet, I would encourage you to check out my earlier post on the topic (thread started about 2 weeks ago). You might save yourself $15.
 
Priming:How do you see

Hello, On production aircraft, most alodine and priming is accomplished before drill up and fitting of parts. On my first kit (Swearingen SX-300) the parts came alodined, I then epoxy primed all parts. All parts were then labeled with part numbers and position. It was the an easy chore to load everything in the jig, drill, deburr, cleco, and rivet the assy. Note: I am new to this forum and I am always willing to suggest methods or answer questions on most aircraft building topics from airframe constuction to engine installation.
 
Yep, the blue Sharpies also seem to last much longer. Strange indeed! Since they seem to last longer AND show through better, I think I am switching to blue!

Kind of like running red chalk in a chalk line....if you get the red chalk on concrete, as the label says "there is no known means for removal". This is So true. I have a slab I poured for my BBQ smoker about 10-years ago. It still has red chalk lines on it!
 
Red line on your patio... That's kind of funny... especially since it isn't my patio! I bet you see that line every time you go out--I would! :) The best thing about building an airplane is that I learn all kinds of other things not to do!

Steve
 
Engraving, Anyone??

My RV7 plans call for lightly engraving markings on the components. Since that is what Van's recommends (see his directions under PRIMING) how many have gone that route?
 
Engraving Pencil

rswalden said:
My RV7 plans call for lightly engraving markings on the components. Since that is what Van's recommends (see his directions under PRIMING) how many have gone that route?

I got a cheap little engraving pencil from Harbor Freight. I used that on most stuff. Just engraved light little marks or numbers or letters or whatever on rib webs, etc.

)_( Dan
RV-7 N714D
http://www.rvproject.com
 
rswalden said:
My RV7 plans call for lightly engraving markings on the components. Since that is what Van's recommends (see his directions under PRIMING) how many have gone that route?

This is interesting, my version of the manual, section 5C specifically says NOT to scribe your reference marks onto the pieces--that you should only use a sharpie marker.

Is there a difference between "scribing" and "engraving"?

I suspect "lightly" engraving would not be a problem, but Van's does specifically say to NOT engrave or scribe period--at least in this section of my -9 manual.

That said, I'd love to be able to scribe them in (because they won't be washed off with lacquer thinner.)

Steve
 
Wouldn't scribing be something like using an awl to scratch the mark into the skin? Engraving using the engraver to "Buzz" it in? I'd imagine that the engraving tool would be less stressful to the piece but I'd still think twice (Call vans) before going at my airplane parts like that.
Jeff
 
I also read the "Never use anything to scribe or scratch" while reading the preview plans. Then when I was building my horizontal stabilizer I read the following on page 6-1 of the RV-8 manual:

"Mark all the parts in the rear spar assembly so they can be returned to their previous positions. Use a Sharpie pen or equivalent for all marks on aluminum, but in this case the ink will be lost if you clean the parts for priming. Despite earlier admonitions about scribing or scratching aluminum, it is permissible to use a vibrating pencil or a system of light punch marks to make identifying marks that will be visible after priming".

If you don't have or want to use an electric pencil, simply remark each part with a blue sharpie if you wipe off the original mark while cleaning for primer. I have been using Sherwin Williams self etching primer and my original blue sharpie markings have shown right through with no problem.
 
To Engrave or Not to Engrave: Ask the Scribes

alpinelakespilot2000 said:
This is interesting, my version of the manual, section 5C specifically says NOT to scribe your reference marks onto the pieces--that you should only use a sharpie marker.......
Steve

Steve--I'm building an RV-7. Yes, my generic instructions under section 5C gives the same NOT-to warning about scribing that yours does. But Van gives a caveat in the very next section directing the construction of the REAR SPAR ASSEMBLY of the Horizontal Stabilizer:

"Use a Sharpie pen or equivalent for all marks on aluminum, but in this case the ink will be lost if you clean the parts for priming. Despite earlier admonitions about scribing or scratching aluminum, it is permissable to use a vibrating pencil or a system of light punch marks to make identifying marks that will be visible after priming."

So..... I just bought my electric engraver today.

AND I will use the Sherwin Williams P60 G2 primer I bought at my local paint store. (I know, I know... on the label it says not to use on alclad surfaces...and it also says that a top coat is required). Guess what? I'm using it anyway. Why? Because that's what Van uses.

Van also recommends "that you remove the blue vinyl as soon as practical after inventorying your kit." I'm doing that too, even though the fad seems to leave it on while burning off strips of the stuff along the rivit lines. After a few wasted minutes with my soldering iron, going for the "perfect edge" .... I realized what a time waster that is (but it DOES look cool).

Maybe when I build my NEXT plane, I'll worry about making it perfect. But for now, I have to yield to the original SCRIBE (Van) when it comes to scribing, and all other controversies. :)

Waldo
RV-7
Peachtree City, GA
 
Check out your spars...

Dunno about anybody else, but my spars had the part numbers and some other number engraved/scribed on 'em. If Van's thought scribing numbers in aluminum parts was detrimental, do you think they'd do it on the spars?

)_( Dan
RV-7 N714D
http://www.rvproject.com
 
Stamping

Another way to mark these parts is with a stamp. Harbor Freight sells stamping kits with all the necessary stamps. Generally a good "L", "R", or numeric is all you need. A light tap with a hammer and it's marked. Show's through the primer with no problems. Good for light parts but not so good on the thicker stuff.

Jim
 
Resurrection

Resurrecting this thread since I see exactly the same problem in my future. Does anyone have a practical solution to the problem of dissolving blue sharpie marks when cleaning and prepping parts for primer?

Safety wire to a label seems cumbersome but workable for confusing parts. The stamping route also seems interesting, but I'm wondering if anyone has checked with Van's to make sure this is acceptable and won't weaken the parts.

Thanks!
 
I lay all the parts I'm prepping out on cardboard or paper towels and then label the cardboard/paper right next to the part. Then I just have to make sure I put each part back down in the same spot on the cardboard which isn't hard since I'm usually working by myself. I'll let the parts fully air dry before remarking them, or if I'm impatient I'll dry a spot off with a paper towel and then relabel them.

This only gets difficult when working with part that is completely symmetrical. Then I really have to pay attention to its orientation while I am prepping it so that I can properly relabel up, down, etc.
 
Various ways...

I will freshly mark with sharpie just before I go through the alumi-prep / alodine step, and sometimes this is still legible (it often is just barely legible shading that you can see with a glancing light). I will re-mark once the alodine has dried, and generally I find that this second mark will bleed through the primer once I spray that on. Also, I do things in order, e.g. my wing ribs were numbered from inboard to outboard, and I start at number 1. For items that are very similar (like W-925 A/B/C Flap Brackets) I daisy chain all the parts for each station with safety wire and also do them in order. I've also tied safety wire into a specific hole in round parts so I get the orientation 100% when it gets re-assembled, after the alodine / priming is done.

Yes, there are some parts that are interchangeable, until the final drilling / dimpling is done then they're definitely a one side only part, and I am a little more careful with these, sometimes I'll mark them in 2 or 3 spots with L/R or top / bottom.
 
Sometimes you can just place the parts that can provide that info. So, for the right side part place it on the right and the left side on the left. Then after you prime remark the parts. You can also mark on the surface where you are priming. I have a plastic sheet on my garage floor which is covered with cardboard. Mark with a sharpie near the parts.
 
Labeling

I will freshly mark with sharpie just before I go through the alumi-prep / alodine step, and sometimes this is still legible (it often is just barely legible shading that you can see with a glancing light). I will re-mark once the alodine has dried, and generally I find that this second mark will bleed through the primer once I spray that on. Also, I do things in order, e.g. my wing ribs were numbered from inboard to outboard, and I start at number 1. For items that are very similar (like W-925 A/B/C Flap Brackets) I daisy chain all the parts for each station with safety wire and also do them in order. I've also tied safety wire into a specific hole in round parts so I get the orientation 100% when it gets re-assembled, after the alodine / priming is done.

Yes, there are some parts that are interchangeable, until the final drilling / dimpling is done then they're definitely a one side only part, and I am a little more careful with these, sometimes I'll mark them in 2 or 3 spots with L/R or top / bottom.

Basically the same. I always labeled on flanges where parts would cover the markings. OCD. Even after cleaning, there was enough marking to remark and they show through P60G2 easily.
 
Sharpie marks got cleaned up with the pre-prime cleaning process. I'd reapply them. They show up fairly well after spraying with SEM rattle-can primer.

One thing to keep in mind, by the time the parts are primed, they aren't too far from assembly. They might not need much in the way of markings.

Dave
 
I used my automatic center punch to leave a light mark on the parts. One dot was left, two dots was right. Had to get creative with marking for wing ribs, lots of little dots.
 
Just me

I normal mark the parts with a sharpie. When prepping for priming, I lightly scrub the parts with a scotchbrite pad, clean with acetone and spray. If i forget to remark the parts after the acetone wipe, I can usually see the area that was marked thru the primer because the scotchbrite texture will not be as intense were the marking was.

Also there are lots of custom parts where you make a left and a right out of chunks of metal. For those I have a letter stamp and stamp the parts during manufacture so that they are forever marked.
 
I used my automatic center punch to leave a light mark on the parts. One dot was left, two dots was right. Had to get creative with marking for wing ribs, lots of little dots.

I was actually thinking of something along those lines for the easy-to-confuse parts. Has anyone tried one of these stamps? doesn't seem like that would do any more damage than a center punch and you could add the correct number.

I just prepped the -14 vert stab for priming today. There's nothing in that lot that can get confused, but I can see several areas of confusion down the road. I'm using Bon Ami followed by acetone - both of which make great Sharpie-erasers.
 
For my HS, I had two plastic bins, one marked ?upper and Left? one marked ?lower and right?. It it was a left part or upper part, it went in one bin. Then I cleaned and primed the parts separate work sessions.
 
Labeling

Here's my labeling scheme in one photo. It worked for every part.
The two vectors point "Up" or "Forward" and "Inboard" but it doesn't matter as long as it's consistent.
The top line is the actual part number from the plans. Important because lots of parts are "L" or "R" but it's actually the direction the flanges face.
The bottom line is which side of the airplane (if needed) and a numerical designator if more than one. Often the top line is all that is needed.
Notice for the sample, it would probably the first left wing rib inboard. Yes, just a sample.
I wrote it on a flange in two places. When prep came, scrub one, dry, replace. The second was a backup. Once assembled, flange markings were covered so there are no visible markings inside.
7GM3AXBm.jpg
 
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Scribe and sharpie

I just lightly scribe my parts with the vibrating pencil and then run a sharpie over the scribe, after cleaning and priming the blue still bleeds through just a little.
 
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