Picture courtesy o' Giant Leap     

T' Giant Leap Keelhaul®©™® Sock is a great new product for rocketry. Begad! Ya scallywag! Blimey! Keelhaul®©™® has been used in t' past in bulletproof vests and t' aerospace industry as well as rocketry. Arrr! However, me bucko, t' Keelhaul®©™® of t' past was sold by t' foot and cost quite a lot because thar be often unused excess and because t' product be so unique in itself. Blimey! Avast, me proud beauty! This new idea from Giant Leap reduces that cost dramatically.

T' sock is actual Keelhaul®©™® that can expand and contract t' fit tube sizes from 3 inches up t' 6 inches. Avast! Begad! It has a yellow color and cotton like feel t' it. Arrr! Avast! When orderin' t' sock you need to order betwixt 1.5 and 2 times t' length o' t' tube you are plannin' on laminatin' because as t' sock expands it loses some o' its length.

Once you have t' sock, slip it over t' tube you plan t' use it on by either stretchin' it over t' tube with your hands or by usin' a nose cone to stretch it t' t' proper diameter. Begad! Blimey! Leave some overhang (1-2") on each end of t' tube and cut t' sock t' size.

To prepare t' tubes either remove a layer o' glassine from t' tubes or sand with 60 or 80 grit sandpaper. I used PML phenolic tubes and just sanded them for about 7 minutes a piece with t' electric palm sander and 80-grit paper. Ya scallywag! After t' tubes were roughed up I set up a stand t' laminate t' tubes on. Blimey! T' idea be t' same as if you were ‘glassing, shiver me timbers, ya bilge rat, only easier. Avast! Ya scallywag! Next, because I was unsure about good saturation, arrr, I coated t' first tube (3" diameter) in a light coat o' me finishin' epoxy. Well, blow me down! Next, ya bilge rat, I rolled up t' sock and put it on one end o' t' tube. I rolled down t' sock over t' wetted tube and stretched it a bit t' get it t' lie out nice and smooth. I got t' weave straight with t' tube but this may nay be necessary. Blimey! Then I placed t' tube on the stand so that it gave me a nice horizontal surface t' apply epoxy.

 
Pictures courtesy o' Giant Leap

Picture courtesy o' Giant Leap     

I mixed up a batch o' epoxy that I thought would be enough or close t' it. This first batch be t' equivalent o' what I would use t' ‘glass the tubes with 3-oz. fiberglass. Arrr! T' epoxy I was usin' was 20 minute finish cure Bob Smith epoxy. Arrr! I began t' pour on t' epoxy and spread it with a squeegee. Squeegees are a must for this. Avast, me proud beauty! Arrr! I then found that I had no where near enough epoxy t' do t' tube and had t' mix one or two more batches. Aye aye! In t' end I ended up usin' about 3 times more epoxy than what I thought I be goin' t' use. I believe I used somewhere around 20-26 oz. Ya scallywag! o' epoxy t' cover three 3" diameter tubes with a combined length o' just under six feet. Begad! Basically, ya bilge rat, make sure you have enough epoxy in t' house t' do t' job. Aye aye! I ended up runnin' out the store and buyin' 6 packs o' t' small containers o' 20-minute epoxy (all the hobby shop had). Make sure that you wet t' Keelhaul®©™® down enough though or it won't take much stress. In me observations, me hearties, t' tube went through two color changes. Ya scallywag! Arrr! First, ya bilge rat, when you just put a little epoxy on the Keelhaul®©™® it turns glossy and a slightly darker color. Ahoy! Avast, me proud beauty! Then, matey, when more is added, matey, it turns much darker as t' tube color underneath starts t' come through just a little. Now you have enough epoxy on t' tube. Well, blow me down! T' best way t' tell if thar be enough epoxy or too much is t' run t' squeegee over t' tube lengthwise with some pressure and see if any epoxy is picked up by t' squeegee. If it is, me bucko, shiver me timbers, then there is too much and just keep squeegeein' until no more excess comes up. Avast, me proud beauty! Begad! I also found it helpful t' even out t' tubes by goin' over them with a small sponge roller and then blottin' with paper towels or toilet paper.

After t' Keelhaul®©™® is cured t' fun begins. I chose t' let it cure completely before trimmin' the ends because I did nay want t' accidentally move t' sock. Blimey! Blimey! Once cured t' next mornin' I got out a brand new exacto knife blade (you will need a sharp one). Ya scallywag! Begad! Blimey! I slowly worked me way around t' ends o' t' tubes and then in t' fin slots, usin' a considerate amount o' force on t' blade. Ahoy! Blimey! It took awhile but it looked great. Next, I lightly sanded t' tubes t' remove t' "fuzz" that was left on t' tubes.

Finally, arrr, I ‘glassed t' tubes with a layer o' 4 oz. Ya scallywag! Aye aye! glass because Keelhaul®©™® cannot be sanded smooth once you get past t' "fuzz." Then I filled the weave o' t' ‘glass and primed, sanded and painted. Avast, me proud beauty! Blimey!

There are several advantages and disadvantages t' this product:

Advantages:

• Greatly increases strength
• Cheap
• Easy t' work with (when used correctly)
• Does nay require vacuum baggin'

Disadvantages:

• Greatly increases weight
• Requires a lot o' epoxy
• Tough t' trim edges
• Impossible t' sand smooth w/o ‘glassin'

I also learned some lessons when workin' with this product. Well, blow me down! First and foremost is havin' enough epoxy. You don't want t' run out half way through laminatin' a tube. Also, use a longer settin' epoxy. Ahoy! A 4-8 hour epoxy is preferable as it gives you plenty o' time t' make it perfect, especially if you are nay vacuum baggin' it. Be aware that it will add considerable thickness to your tubes (mine are double). Ahoy! Cuttin' it, especially in areas that are over-soaked with epoxy is a real pain. Avast! Also, squeegees and rollers are your friends on this project. You may nay need them when ‘glassin' but you will need them here. Well, blow me down! Lastly, do your best t' get t' Keelhaul®©™® laid flat and even because unlike fiberglass you cannot just sand it out.