johnboyrc

My airplane club had a float fly this past weekend, and I decided to take the swamp buggy out since my plane is still being finished. After the first run on the water, I noticed the bottom ply had cracked at the seam. I put packaging tape on the length of the seam to make it through a few more runs, and that helped, but I got a few more cracks in other places. The wood grain also started to show through the paint.
I have little experience with fiberglass, but I am thinking of sanding the bottom down, and then try to fiberglass it. What would be the ideal weight of fiberglass to use.

dadkins

As light as possible - depending on what engine you are running.
I did mine with heavy cloth - just the sponsons- not the tunnel. and only up the mid piont where the top and bottom join . This added a lot of weight but made it MUCH more durable for snow running. It is a dog in the water with a .40 on it.

Mr Cajun Gator

It can also be repaired by sanding off the paint then open the cracks just a little, then epoxy with some good 30 minute.

ballgunner

My Feedback: (1)

My Windy is starting to show signs of wear. I ran it onto a rock and capsized it. Brought it home and redid the paint and ran it a bit and it started to show signs of cracking at the seams. Being an old hand at sailboats I am obsessed with making everything fair. Results in some thin seams from sanding too much. I pried open some seams and filled them with epoxy and repainted. It is starting to crack again. I will build another because it's a nice little boat. Next time all seams will be glassed. Big Swamp Buggy = all glassed seams = no problems.

johnboyrc

I epoxied a few minor spots after the last time I ran it. Worked for a few runs but eventually failed. Running a big swamp buggy with an OS 60FP makes the water hit the bottom hard at times. I agree that all seams should be glassed, but I wonder what is adequate.
When I painted this swamp buggy, I used lustrekote, and it added a lot of weight. So repainting it with a lighter and more durable paint would help.
I thought about running it on snow, but was always worried that the bottom would get scratched, or a skin would pop off.

2manytoyz

After a few runs with my Windy, I had the same issues. I used about a 1" wide strip of fiberglass cloth, and beefed up all the joints. It lasted a few good seasons before I finally retired it. If you find it's a dog, add a bigger motor! I ran a .20 on my Windy. I just ordered a Big Swamp Buggy kit, and a .60 to power it. I will be fiberglassing all the seams before it leaves my workshop.

n8mkr

2Many:
Are you glassing the joints inside or outside, or both? I am building my BSB right now.
John

FlyingPilgrim

My Feedback: (26)

I just ordered one of these (BSB) for my son for Christmas, so I am glad to see this old thread revived. I believe the best engine would be a light weight .60/.61, probably bushing instead of bearing to keep it light and low maint. in case it gets wet, appreciate any suggestions from those that have run this before. Not sure if it's an issue or not, but I would think overpowering this might be a bad thing if it gets too much torque as it may want to flip it sideways (stay away from a 4-stroke for that reason?). Maybe an LA .65 or an old .60 FP?

I usually glass my boats exterior with 3/4 oz glass cloth with polyester resin, plan to do the same with this (add strength and gives nice smooth finish). Might be a good model to try the Klass Kote epoxy paint on. Sounds like it's the best option next to expensive automotive urathanes.

500 lb. koolaid man

FlyingPilgrim, consider a tower hobbies .61, from the little bit of research I've done it's a reliable engine and the lightest I've seen, my Dumas Big Swamp Buggy project will soon have a tower .61 or .75($5 more).
http://www3.towerhobbies.com/cgi-bin...&I=LXUR77&P=ML

n8mkr

Pilgrim:
I have been posting in the following thread:

http://www.rcuniverse.com/forum/m_54...tm.htm#5425501

I have found it to have some of the best pix by BadAzzSwampBuggy that I have seen. Has helped me with my assembly so far. I have posted my pix there to and will continue to. I would like to see some of your glassing as you go. Please take some pix.

John

2manytoyz

Just the outside. The inside gets fillets of epoxy on the ribs. I found that the hull flexing on my Windy caused cracking along the pylon seams. Please understand I ABUSED my Windy a lot. Ran it on dry land almost as much as on the water, jumped the bank, etc.

Also, FWIW, two of my buddies ran BSBs with .61 engines. The problem for both of them wasn't torque twisting it sideways, but rather an incorrect thrust angle on the motor. Both had a problem with flipping over backwards with too much speed. It would start to porpoise, and if they didn't get off the throttle, the nose would get air under it and the result was a big flip.

Full throttle could be applied from a dead stop with no issues of twisting sideways. Wide enough and bouyant enough to handle the twist.

And before anyone asks, NO I haven't finished mine! Since I last posted, got married (again), bought a house (again), and have had a full plate the last couple of years. I still have this project on the back burner. Starting to cool off in the garage finally, so might have to revive this one.

Problem in my area is lack of places to go. They have put up a fence around practically every puddle in our county. Wouldn't want little Johnny to drowned somewhere. Uh, this is Florida, we have rivers, an ocean, and the gulf, so stop fencing in all the ponds!!! Geez. [sm=drowning.gif]

Some vintage pics...





Sorry for the blur, but you can see this one is nose up, and not far from flipping:



[sm=shades_smile.gif]

TERBObob

My Feedback: (21)

One more item you might want to consier using ..
2 part hobby foam ( NOT the shaker can stuff ! )
This stuff , when dried , adds a LOT of strength to your hull/seams , and IS lightweight . When added , it kinda "glues" itself to your bare wood , and not only strengthens it , but also seals it as well .
You can use it to fill the entire insides of the hull , or just in the areas you want the added strength .

FlyingPilgrim

My Feedback: (26)

Koolaid, thanks, I was looking at the Tower engine as well. Lighter weight than some others, and the price is right.

John, thanks for link to other thread, I'll be watching there as well. I'll post pics of glassing, but it won't be 'til after the new year, as this is a Christmas present. My wife hates the resin because it stinks the house up for a day or so. It works well, though.

2manytoyz, glad to hear there is no concern about the torque wanting to roll the boat. I may opt for a .75 since it doesn't sound like it will be an issue.

Appreciate the good info!

n8mkr

I decided to also do some fiberglassing on the inside as well. Here is some reinforcement to the bottom flat ply on the inside.