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! Blimey! T' rings were for a BT-50 and nay a BT-20. I thought about replacin' t' rings with a correct set, but then t' creative juices started t' flow, what could I do with this kit? I had always wanted t' build a Big Bertha but had never purchased t' kit. Arrr! Blimey! Begad! Blimey! With t' parts in t' Baby Bertha, I could substitute a longer body tube and build t' Big Bertha with a 24mm motor mount. Ahoy! Blimey! Ya scallywag! Blimey! But that had already been done and besides, I'm cheap. Aye aye! Blimey! I like t' less expensive motors. Begad! Blimey! So that still left t' question, 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. Ahoy! Blimey! T' first item be t' make t' boat tail and t' baffle assembly. Arrr! 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. Begad! This fits inside a longer BT-50 tube. Ahoy! T' BT-50 tube is 8 inches long and slides down even t' t' aft end o' t' BT-20 motor mount. Ya scallywag! 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. Avast, me proud beauty! There are 8 holes spaced around t' top sides o' t' BT-50 tube, me hearties, 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. 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, me hearties, four triangular balsa supports are glued t' support t' paper boat tail and t' fins when they are attached later. Arrr! These supports have an 1/8" section that is square and fits under t' outer body tube. Avast! Avast! 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. I made a paper reducer for t' boat tail t' old fashioned way usin' a compass and calculations that I found in a book. Ya scallywag! Ahoy! I used two o' these paper shrouds on top o' each other t' stiffen them up. Ahoy! Ya scallywag! I then coated t' paper with Crazy Glue. After t' shrouds are in place and dry, me bucko, shiver me timbers, I added t' fins with little triangular pieces o' balsa on t' ends t' match t' angle o' t' boat tail. Avast! T' shock cord was 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, shiver me timbers, t' read, "BBertha".

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

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

This time I noticed that t' fins were nay adherin' t' t' boat tail well. 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, sanded t' tube well t' rough it up, me bucko, arrr, me hearties, 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. Durin' this process I decided t' replace t' fin that was split in two and repaint t' lower part o' t' rocket.

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

Summary:
Try and try again. Blimey! Blimey! It was startin' t' get frustratin' seein' me rocket lose fins on each launch, shiver me timbers, however, matey, 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. 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. Arrr! Blimey! (I still am nay brave enough t' fly without any waddin' at all though.)

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