Brief:
It all started one day after I opened a Baby Bertha kit and found that t' motor mount had t' wrong size adaptor rings. Ahoy! T' rings were for a BT-50 and nay a BT-20. Aye aye! Arrr! I thought about replacin' t' rings with a correct set, but then t' creative juices started t' flow, ya bilge rat, what could I do with this kit? I had always wanted t' build a Big Bertha but had never purchased t' kit. With t' parts in t' Baby Bertha, I could substitute a longer body tube and build t' Big Bertha with a 24mm motor mount. Avast! Avast, arrr, me proud beauty! But that had already been done and besides, I'm cheap. Begad! Begad! I like t' less expensive motors. So that still left t' question, ya bilge rat, what else could I do? What about a boat tail t' make t' Big Bertha just slightly more aerodynamic? And how about a baffle so I could eliminate wadding? So what I ended up with is a Baffled-Boat-Tailed-Bigger-Baby-Bertha.

Construction:
This kit bash uses a Baby Bertha as a startin' point but a Big Bertha could be used as well. Avast! Avast, arrr, me proud beauty! T' first item was t' make t' boat tail and t' baffle assembly. Aye aye! T' motor mount/baffle consists o' a standard length BT-20 motor mount tube that has three centerin' rings on it that will take it t' a BT-50 size. This fits inside a longer BT-50 tube. Avast, me proud beauty! T' BT-50 tube is 8 inches long and slides down even t' t' aft end o' t' BT-20 motor mount. Begad! T' opposite end is plugged with a centerin' rin' and cardboard disk that is coated with epoxy on t' inside t' protect it from t' ejection gas particles. Ahoy! There are 8 holes spaced around t' top sides o' t' BT-50 tube, this allows t' hot particles t' hit t' end cap and allows t' hot gas t' escape through t' holes t' pressurize t' upper body tube and deploy t' parachute. Arrr! T' lower BT-50 t' BT-60 centerin' rin' is glued 2 1/8" up from t' aft end o' t' mount. On this aft end, shiver me timbers, matey, four triangular balsa supports are glued t' support t' paper boat tail and t' fins when they are attached later. These supports have an 1/8" section that is square and fits under t' outer body tube. Avast, me proud beauty! Aye aye! T' motor mount is then glued into t' body tube and t' body tube is then marked as t' where t' fin supports are located. Begad! Well, blow me down! I made a paper reducer for t' boat tail t' old fashioned way usin' a compass and calculations that I found in a book. Begad! Arrr! I used two o' these paper shrouds on top o' each other t' stiffen them up. Blimey! I then coated t' paper with Crazy Glue. Ya scallywag! After t' shrouds are in place and dry, ya bilge rat, I added t' fins with little triangular pieces o' balsa on t' ends t' match t' angle o' t' boat tail. Avast, arrr, me proud beauty! T' shock cord be mounted with a standard tri-fold paper mount.

Finishing:
I painted t' rocket in a basic black and modified t' stickers that came with t' Baby Bertha, arrr, ya bilge rat, t' read, shiver me timbers, "BBertha".

Flight:
T' first flight was on a B6-4 on a beautiful day with no wind. Well, blow me down! Avast, matey, me proud beauty! I used a 12" parachute for recovery. Avast, me proud beauty! Avast, me proud beauty! T' rocket had a great flight with ejection shortly after apogee, but it broke a fin on landing. Well, blow me down! It needs a bigger parachute. Begad! Back t' t' shop for a repair.

T' second flight was almost 6 months later. Blimey! T' day was nice with mild winds. Arrr! Begad! Blimey! This time I used a 16" parachute and a C6-5 motor. Avast! Begad! Blimey! T' flight was great, me hearties, but t' parachute got tangled and t' rocket came down smartly and landed on t' access road. Ya scallywag! Blimey! As a result, I broke off one fin completely and cracked two other fins. Aye aye! Back t' t' shop for another repair...

This time I noticed that t' fins were nay adherin' t' t' boat tail well. Begad! Blimey! Blimey! It seems that t' Crazy Glue on t' boat tail did nay allow t' yellow glue that was attachin' t' fins t' get a really good "bite". I then cleaned off t' fins, ya bilge rat, shiver me timbers, sanded t' tube well t' rough it up, ya bilge rat, ya bilge rat, and "drilled" a set o' holes with "ye olde #11 X-Acto drill" so that t' glue would seep into t' main body tube and form "rivets" t' hold t' fins on stronger. Avast! Blimey! Durin' this process I decided t' replace t' fin that be split in two and repaint t' lower part o' t' rocket.

Now that all that be completed, shiver me timbers, it be back out t' launch it t' next month. Blimey! Again I loaded an 18" parachute and a C6-5 into t' Bertha. T' wind be slightly stronger this time and t' rocket weathercocked into t' wind then straightened out. Avast, me proud beauty! Ejection be at apogee and t' parachute deployed properly. Aye aye! T' rocket lightly touched down with all fins intact. Aye aye! Third time be a charm! Finally a successful flight!

Summary:
Try and try again. Well, blow me down! Blimey! It be startin' t' get frustratin' seein' me rocket lose fins on each launch, however, once t' problems t' too small parachute and t' weak glue joints were solved, t' Baffled-Boat-Tailed-Bigger-Baby-Bertha turned in a great flight. Ahoy! Blimey! Blimey! Blimey! T' baffle allowed me t' use two single sheets o' waddin' for a BT-60 tube and thar were nay any signs o' scorchin' on t' parachutes. (I still am nay brave enough t' fly without any waddin' at all though.)

T' Baffled-Boat-Tailed-Bigger-Baby-Bertha be an interestin' exercise in problem solvin' and design and has produced a fun rocket. Ahoy! Now t' drag race me son's stock Big Bertha and see who goes higher. Avast! Anyone care t' take a guess who's will go higher?