DC, I am sure you could use the plastic in the box to fill in gaps and seams. The rule only says “may fill in seams and gaps”, it doesn’t spell out any specific substance that HAS to be used to do so. (if you look closely at the rules, it doesn’t allow “using everything in the box”, if says “parts that come in the box”, everyone knows that the sprues are not “parts”)
I’d enter OOB, just to get more models done to take to the show. Then, the best way to actually compete is to build a nearly OOB kit, and add whatever “NOOB” weapons or add-ons that I want, that are made from plastic or simple resin shapes. (such and bombs, etc) (NOOB is “not out of the box”, lol) You enter the Not-OOB builds into the open classes.
Since the IPMS judging is “who has the least mistakes”, that puts plastic models with very basic add-ons, on the table competing with Photo-etch, Resin, Vac parts. It is easier to make an error when you have 3 or more different media, especially if you have to cut plastic out of the way for the resin and etch.
So, it is sort of a “race not to get there first”, with “first” being the errors being found by the judges as they make their cut. Putting almost all plastic models up against the resin and etch enhanced builds in the open categories almost seems like ‘cheating’, sometimes,but, is completely within the rules and spirit of the contest.
So, I take a few with me,some for 1/72 jets, some for 1/72 props, then some OOB, just to have a mix. Even though most of my models are OOB or OOB+a little. Conversions I just will keep at home,it is too easy to miss a ridge between some nose and fuselage, or sand some soft vac parts too deep after they are glued to plastic or resin.
Just for grins, print that “OOB page” of the rules I linked to, cut off all the parts that aren’t OOB rules,and make letters or numbers next to each part,and then write down some thoughts you have about any certain model. By going from your list back to your numbered lines, you will see both how much you can do in the pursuit of a “good model”, and all the things that the rules obviously spell out that you can’t do.
I did just that back in 2013, I had read so much about how the rules didn’t work to build good models if they were going to be OOB. After taking those notes, and comparing my ideas, I discovered that building “a competitive OOB model” was going to IMPROVE my models, not detract from them. Taking a couple of models to a G-S-B contest will open the eyes a bunch, too. Especially if you think you build “10-point” models, and you get model score sheets from the judge that you only scored 6 out of 10 points on. That is a real reality check.
I routinely tell people at the shows when we get talking and joking around, that I am one of the best Copper, Lead or Pewter modelers in the show hall.
Rex
(a note, CAPS aren’t being used to shout in this post, just for emphasis)