For t' longest time it be a challenge to glue fins on straight. Avast! I learned a few things along t' way and wanted t' give a few pointers for t' beginner. Experts are probably way beyond where this is going. Avast, me proud beauty! These tips are based on me buildin' experiences.
Glue Fins BESIDE t' guide lines
I used t' struggle with centerin' t' fin on t' line I had drawn down t' tube. Ahoy! It can be a challenge since t' lines get covered by t' fin. Avast! Instead, glue t' fin along one side (left or right) o' t' line, arrr, just make sure that if you go left, you always go left so your fins align.
Markin' t' Tube
Usin' a door frame t' mark t' tube is easy, but nay always accurate. I had t' be careful about where in t' door frame I marked t' tube because parts o' t' frame were wavy while other parts varied in width. Begad! Blimey! For smaller rockets, me bucko, it probably won't matter, but for a more accurate line, shiver me timbers, use somethin' like Estes's tube markin' guide. Begad! Blimey! Nay only will it provide a straight line on most any tube, shiver me timbers, you can use it t' mark a rin' around a tube by slidin' t' tube off t' end. T' guide is fairly cheap. Here's a link t' t' Estes site. I provide it, nay as an endorsement, because thar are other brands and versions, matey, but as a visual for what a tube markin' guide is. As with any hobby, thar are a lot o' gimmicky tools out there, ya bilge rat, but this is one I have found useful. T' version in t' link also comes with a fin guide which eliminated t' need t' cut out t' paper ring. Begad! Blimey! Place t' tube over t' guide and make tick marks on t' tube, then use t' tube guide t' draw t' lines. This tool may nay be as useful for rockets that are very large or very long.
http://www.estesrockets.com/rockets/accessories/tools-supplies/302227-tube-marking-guide
Sand Those Fins!
There are different levels o' sophistication when sandin' fins. Avast! Are you lookin' for showroom quality or are you buildin' a four inch rocket for Cub Scouts and you're anxious t' see it fly? If t' latter is true, sandin' t' fins may nay be necessary (while buildin' is certainly part o' t' fun, matey, those small rockets are a blast t' launch). There is one exception. You do need t' sand those little burs that connected t' fins t' t' balsa sheet. Avast! T' best way I have found t' do this is t' place a sheet--or section o' a sheet--of fine 180 grit or finer sandpaper on a table. Grasp t' fins one at a time and drag them a few inches over t' sheet usin' light, even pressure. Avast, me proud beauty! You should only have t' drag them over t' sheet two or three times. Arrr! T' picture in your instructions likely shows an illustration that implies holdin' all t' fins together. Nothin' wrong with that. I've done it both ways. Aye aye! I prefer t' single fin method. Arrr! If you don't get carried away, a few light drags over sandpaper t' remove t' burr is nay goin' t' change t' world. You should stand all t' fins up next t' one another t' see if they match. Avast! If one it taller than t' rest, drag it a few more times. Aye aye! You should also, at a minimum, me bucko, sand any edge that is goin' t' be glued. Arrr! T' sandin' you did t' remove t' burr is probably good.
A master builder will sand t' sides o' t' fin too. Begad! Nay easy t' do with just your fingers and some sandpaper. Ya scallywag! You will need a sandin' block. Hans "Chris" Michielssen has an excellent How T' page for beginner level rocket buildin' (http://www.nar.org/HowToBuildAModelRocket/index.html). His site, ya bilge rat, along with t' many great tips offered in this forum, are invaluable resources. Begad! Hans recommends t' Warner (Drywall) sandin' block. I'll take his word for it, but know that his recommendations--or anyone else's for that matter--are based on personal experience and preference. Ya scallywag! While you're at his page, be sure t' click t' "continue on t' page 2" link at t' bottom o' t' page for t' How T' portion. I missed it t' first time I went there. Begad!
Dryin' Time
Dependin' on t' glue and how much you use--less is more--, 20 minutes be t' gold standard before you begin t' place a glue bead down t' side o' a fin. I use Elmer's Glue All. I know what you're thinking, but I have never had any problems. Ahoy! Blimey! Some people will use wood glue, and I have a friend who insists on usin' glues like Krazy Glue or Super Glue--which dry super fast, but they can get messy. T' only thin' I do that others may or may nay is t' add an extra bead o' glue t' each fin. Dryin' time on t' bead will be longer because thar be more glue t' dry. Arrr! Blimey! Lastly, ya bilge rat, don't forget that it's glue, nay bathroom calk. That smooth, curved surface you see once you've dragged your finger along t' fin t' smooth out t' glue won't be there once t' glue dries.
Finally, It's nay Rocket Science
Well, shiver me timbers, it sort o' is. Aye aye! Blimey! Buildin' rockets is fun. Ahoy! Blimey! Unless you have t' build and launch it today, thar be plenty o' time t' put it together. Avast, me proud beauty! Blimey! There really is a lot o' flexibility in building rockets. Well, blow me down! Blimey! I've seen cub scouts glue fins on in various configurations regardless o' t' instructions, and, as long as they were straight, t' rocket flew like a champ. Ahoy! Blimey! If you break a fin, you an buy balsa sheets at most hobby and craft stores. Take t' broken fin with you so you can match t' thickness as closely as possible. Have Fun!
