Brief:
For a long time now, me favorite rockets have been military missiles. Arrr! Ahoy! I have built many in t' past and wanted t' build a HPR version o' t' Harpoon AGM-84. I decided t' scratch build, since thar were no kits t' fit t' bill, ya bilge rat, matey, arrr, and designed a 4" 33% Scale Harpoon AGM-84. T' rocket has a 38mm motor mount, 54" PML parachute, shiver me timbers, Nomex ® cloth, Keelhaul®©™ ® for shock cord and a detailed scale set o' decals. Ahoy! Blimey!

T' body tube is made o' PML 4" Quantum tubing, which I had custom slotted and cut at t' factory. Ya scallywag! They did their usual great job, me bucko, ya bilge rat, and they followed me cutting/slottin' instructions t' t' tee! Hats off t' t' guys at PML. Begad!

This will be t' first t' be built in a series o' 4" models I have designed and are on t' buildin' board. Well, blow me down! I did check t' WPAFB Museum website and they have one o' every missile I have interest in on site, me bucko, arrr, ya bilge rat, with the exception o' this one. Aye aye! Ya scallywag! For some reason, it couldn't be that this is primarily a Navy missile, ya bilge rat, I had a hard time findin' pics for it so I could do scale decals. Some good pics were found and I be able t' create some decals that are very close t' scale. Begad!

Construction:

Construction began by cuttin' t' 38mm motor mount tube t' 23.75". Avast! Then I measured and glued t' first centerin' ring, which be t' lower o' two rings for t' center fins. Both sets o' fins are sandwiched betwixt centerin' rings. Well, blow me down! Next, shiver me timbers, I cut out the fins from t' RockSim pattern I printed out from t' design. Usin' a Dremel, asbestos cuttin' wheel, me bucko, me bucko, and a vacuum t' pull in t' dust while I cut, all four upper fins and four lower fins were cut with ease from t' G10 sheeting. Blimey! They were final sanded on me table sander and now fit t' slots well. After cuttin' me own G10 fins, matey, I highly recommend this t' anyone who wishes to scratch build; it will save you a fortune over pre-cut fins and are very easy and fast t' make. Avast, me proud beauty!

T' four inch coupler was cut t' a length o' 7" and edges were sanded. Finally, I measured t' 1/2" thick by six inch centerin' ring, which will extend past t' aft o' t' body tube as a boattail. Blimey! It was reduced t' 4" in diameter, so it would fit flush with t' outside o' t' body tube. Aye aye! Avast, me proud beauty! Blimey!

A centerin' ring was mounted t' t' motor mount tube and it be installed in t' body tube after roughin' it up with sandpaper. This CR sits just below t' slots for t' center fins. Ahoy! A second CR was installed just above t' lower fin slots. Ya scallywag! Fin edges were rounded and surfaces were roughed up and t' lower fins were glued in place to the motor mount and upper CR. Aye aye! Also, t' lower fins were glassed from t' motor mount, up t' inside o' each fin and across t' inside o' t' body tube area. In addition, t' lower centerin' rin' be installed flush with t' body tube and against t' bottom o' t' lower fins. Ahoy! Finally, t' lower transition was sanded t' angle t' bottom edge for t' "transition" look.

I worked on the ply 1/2" thick tail transition piece. Blimey! Well, blow me down! 3 holes were drilled through it to accept t' 8/32 sized bolts for t' PML motor retainer. Begad! Begad! I used a 1/2" drill bit t' open a recess in t' top side o' t' transition, then carve it out usin' a dremel and small sandin' tube so t' blind nuts would sit recessed inside this "well". Aye aye! This be necessary so t' piece could be glued flush t' t' bottom CR on t' model. Next, shiver me timbers, shiver me timbers, I placed some glue inside t' recess and installed t' three blind nuts, then tested for a flush fit. Aye aye! Finally, me bucko, the blind nut threads were filled with wax, then t' excess wax be shaved flush and I epoxied t' transition t' t' bottom o' t' rocket and motor mount. Arrr! Upper fins were next; each canard fin was glued t' t' motor mount and lower centerin' ring. I also took t' final centerin' ring, ya bilge rat, t' one that would fit on top o' t' center fins and drilled two holes, then mounted t' Stainless Steel 3" wide U-Bolt for t' shock cord. Ahoy! Aye aye!

Next, ya bilge rat, I glassed each canard fin inside t' t' motor mount and inside body tube, me bucko, then glued in the last centerin' rin' with t' U-Bolt as a top cap t' t' center fins. Arrr! Avast, arrr, me proud beauty! The coupler be installed next, followed by t' upper section o' body tube. Arrr! I ran maskin' tape around t' seam t' help keep both upper an lower body tubes in alignment with each other until t' glue set. I have seen where a coupler has some play and can leave t' joint a bit "out o' round", matey, which leaves a little overlap betwixt t' tubes. Ahoy! Usin' several wraps o' maskin' tape kept it in alignment and t' tape easily pulled off once t' glue has set. Well, blow me down! Blimey! T' coupler adds strength t' t' centerin' rin' since it is holdin' t' rin' down atop the center fins. Begad! This method be used t' insure it had a solid anchor since it has to handle t' stress o' deployment. Ahoy!

Once everythin' had dried, I started glassin' t' lower fins. At this time, one o' four sides is glassed. While t' epoxy was still curin' for t' cloth, shiver me timbers, ya bilge rat, me bucko, I cut t' lower 1/2" launch lug t' a length o' 2 1/2", matey, then epoxied it between t' lower fins, 1" from t' body tube bottom. Aye aye! Ahoy! Next, me hearties, I finished fiberglassin' t' fins, me bucko, ya bilge rat, then added fillets t' t' upper canard fins and mounted the upper launch lug. Arrr!

T' upper fillet sandin' was completed. In addition, me hearties, matey, ya bilge rat, t' seam was sanded smooth and lower fillets were sanded, arrr, but t' cloth edge still needs blended to the body tube. Ya scallywag! Also, t' bottom o' t' boattail plywood be glazed with epoxy. Begad! Begad!

Some work be done on t' Nosecone; if you all have never had t' pleasure of usin' t' RGM Nosecones, you are really missin' out! T' quality is fantastic with a SEAMLESS design, arrr, yes, I said seamless. Ahoy! It was like a rocketeers dream come true! T' nosecone is made from resin and cloth and is yellow in color, similar t' t' resin model airplane and boat kits you can buy. T' quality is excellent, with a good fit at t' base, a molded-in U-Bolt and ultra smooth finish, shiver me timbers, right out o' t' box. They are t' date t' only "round" Nosecone I could find in t' 4" version. Ya scallywag! As a final FYI, Ross at Magnum told me that t' gentleman at RGM lays up all these cones one at a time, matey, by hand! With a price o' $29.95, ya bilge rat, they are about $10 more than a plastic ogive nosecone, but you get what you pay for and it's worth it!

T' nosecone was lightly sanded and washed t' remove any release agents, then one coat o' primer be applied, matey, which came out nice. Begad! No problems were found with t' primer stickin' t' this resin Nosecone. Aye aye! Ahoy!

T' glassin' in t' lower fin area was sanded and blended usin' a dremel power sander, then touched up by hand with 100 grit sandpaper. Plugs were inserted into t' lugs so they would nay get painted inside, then t' holes for the motor retainer were re-drilled out and blind nuts were tapped with an 8/32 tap t' remove t' wax used t' seal t' threads from epoxy.

Finishing:

Three coats of white Krylon primer were applied t' t' body, followed by two coats o' gray Krylon primer. Avast! Blimey! Pinholes were filled next, me hearties, ya bilge rat, then sanded with 220 grit sandpaper. Two more coats o' gray primer were applied, followed by 3 coats o' white primer. Ya scallywag! Blimey! Blimey! Blimey! I am lettin' t' body tube dry overnight and will wetsand it tomorrow, then apply more primer if necessary and t' colors. Finally, me bucko, t' nosecone was given about 6 coats o' primer, me hearties, matey, then wetsanded with 320 grit wet/dry sandpaper; 3 more coats o' white primer were applied t' t' nosecone and left t' dry overnight. Well, blow me down! Blimey!

T' model was wetsanded with 400 grit wet/dry paper, then 600 grit. I painted t' Nosecone first, shiver me timbers, arrr, with 4 coats o' Krylon Glossy White spray paint. Next, t' body tube was painted, me hearties, also with four coats. Avast, me proud beauty! They are both dry, arrr, but I am lettin' it set overnight before paintin' t' stripes. Ahoy! In t' interum, I am workin' on some scale decals for t' Harpoon, me hearties, but need pictures...I don't have any good pictures o' t' letterin' for different sections. Well, blow me down!

T' Harpoon was weighed at our first HPR launch ever for our Cincinnati NAR club. Avast, me proud beauty! I almost fell over when I saw, but knew it be goin' t' be heavy, as I added most o' t' ballast in birdshot that Ken Parker gave me when I be in NC this past summer. Ahoy! It weighed in at 6lbs 7.8oz without motor!!!!! Blimey!

I almost died...goin' t' have t' re-do all me sims t' see if it can handle an I211 because, even though she isn't painted, me hearties, she was goin' t' fly at our HPR Launch, which is a two day event. It will be like flyin' a heavy torpedo, which is what it represents anyway, shiver me timbers, arrr, so what t' heck. Blimey! Arrr! Blimey!

Flight:
I had two launches usin' an I211W for t' Harpoon's maiden flights. Arrr! Blimey! T' first flight was perfect; awesome power and came off t' pad stable, me hearties, lifted well and deployed right at apogee. T' rocket landed safely and t' 54" PML parachute I used worked well and was unmarred due t' t' use o' a Keelhaul®©™® cloth. Ahoy! However, t' second launch had an early ejection. Well, blow me down!

Recovery:
T' nosecone tore off t' cord and plummeted t' t' earth, arrr, yet be recovered after diggin' it out, with only scratches. Arrr! T' rocket landed right on top o' a tree, arrr, about 40 feet up. I spent 7 days tryin' t' retrieve it before it came out of t' tree. Avast, shiver me timbers, me proud beauty!

T' rocket suffered a minor zipper in t' upper body tube, which be easily repaired. Begad! Blimey! I used Keelhaul®©™ ® shock cord for t' model and it came out with no marks at all.

Summary:
T' tube be replaced and I applied all decals for t' Harpoon. Avast! Well, blow me down! Blimey! It really looks good now and will fly again soon. Avast! Anyone interested in military missiles should consider buildin' one o' these. T' file has been uploaded t' EMRR and it's a great flier and real looker. Ya scallywag! Moreover, you can have a set o' decal files with all t' work done simply by sendin' me an email or visitin' Jim Ball's Scale Data website, which should have me decals uploaded soon. Since t' design and decals are complete and it's a good flier, me hearties, most o' your work is already done, so take t' leap and impress t' crowd with this AGM-84 Harpoon.