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crack in fiber glass fuselage

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Old 03-06-2016, 06:02 PM
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Stick 40
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Default crack in fiber glass fuselage



Hi,


I am a little new to fiber glass and wondered what to do with this crack.

its a GMP PRO P-26 and while I was installing the fuel tank, I realized the tank and everything else was mounted under the top of the Fuse. I thought I should put a bracket in it as to hold it better.
The mounts are only attached with 30 min. expoxy.
I made a alum. bracket and installed it using a 6x32 button head bolts, the button heads on the top and would be where the black paint would be for the cockpit.
But I have a small crack in it and wondered what is the best way to repair.
There is a fiberglass strip on the underside, inside the fuse.
I thought of drilling two small holes in each end of the crack and filling with epoxy. just wondered if I should do more.
Pic's did not come thru., it is a small 1/2 in. crack between the two 6x32 button head bolts in the cock pit are, they are on the seam between the two halves.
I will try and post the pics tomorrow.

thanks

sticks

Last edited by Stick 40; 03-06-2016 at 06:29 PM. Reason: pic's
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Old 03-07-2016, 04:49 AM
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jetmech43
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You can take some fiberglass and reinforce from the inside if you can get to it
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Old 03-07-2016, 08:20 AM
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Stick 40
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There is a 2 in wide piece on the inside.
that is why I wondered if that would be enough, if I drill two small holes in the ends of the split.

it won't show much, as it will all be black and the pilot will be in that area.

I tried to post pic's but that did not work, I messed it up somehow. I will try again.

sticks
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Old 03-07-2016, 09:23 AM
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just put a piece of fiberglass patch, should be easy and strong when finished
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Old 03-07-2016, 09:27 AM
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Generally not a good idea to put screws/bolts through fiberglass. You could have used a fiberglass bandage to secure the bracket to the inside of the fuse, just epoxied the bracket in place, or, best yet, used Hysol to secure it. In cases where it is necessary to bolt through the fiberglass, I epoxy an oversize piece of ply or G10 in place on the inside before drilling.

In the case of your bracket, any side-to-side motion in the bracket induced by engine vibration is likely going to cause more issues. I would reconsider whether the bracket is really necessary. A good 30-minute epoxy, assuming you roughed up the inside of the fuse with sandpaper and then cleaned it thoroughly with alcohol, should hold the tank platform just fine.
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Old 03-07-2016, 09:29 AM
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I would just flow a little thin CA in the crack and be done with it. What has happened is the seam has popped in that small area. Wicking thin CA in will re-attach the seaming strip on the inside to the fuse side. I'm pretty sure that fuse is made from polyester so CA will stick really well. In reality, it's a 5 minute fix.
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Old 03-07-2016, 11:24 AM
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I have the Same Peashooter. I also bent the fuse. I tacked 3/4 oz cloth down with a few drops of CA and then used Zap finishing epoxy. It's now stronger than new.
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Old 03-07-2016, 02:21 PM
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Originally Posted by RBACONS View Post
Generally not a good idea to put screws/bolts through fiberglass. You could have used a fiberglass bandage to secure the bracket to the inside of the fuse, just epoxied the bracket in place, or, best yet, used Hysol to secure it. In cases where it is necessary to bolt through the fiberglass, I epoxy an oversize piece of ply or G10 in place on the inside before drilling.

In the case of your bracket, any side-to-side motion in the bracket induced by engine vibration is likely going to cause more issues. I would reconsider whether the bracket is really necessary. A good 30-minute epoxy, assuming you roughed up the inside of the fuse with sandpaper and then cleaned it thoroughly with alcohol, should hold the tank platform just fine.
the two braces were not that secure to start with , the front one for the fuel tank came right loose. No I did not sand paper and clean , I just added 30 min. epoxy.
What is Hysol and where do I get it.
I get the side to side thing, actually I did not think about the fuse being joined in the middle.
I could rough up the cock pit area on the outside and epoxy a thin piece of lite ply on the area and paint it black. Then put the pilot and stuff on that.
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Old 03-07-2016, 03:29 PM
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Originally Posted by Stick 40 View Post
the two braces were not that secure to start with , the front one for the fuel tank came right loose. No I did not sand paper and clean , I just added 30 min. epoxy.
What is Hysol and where do I get it.
I get the side to side thing, actually I did not think about the fuse being joined in the middle.
I could rough up the cock pit area on the outside and epoxy a thin piece of lite ply on the area and paint it black. Then put the pilot and stuff on that.
Dreamworks sells Hysol 9465 It works great for fuse former's and servo trays, pin hinges ect.......
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Old 03-08-2016, 04:59 PM
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Originally Posted by chris923 View Post
I have the Same Peashooter. I also bent the fuse. I tacked 3/4 oz cloth down with a few drops of CA and then used Zap finishing epoxy. It's now stronger than new.
not sure what you mean by Bent the fuse??

second question, if you have flown it how did it fly????
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Old 03-08-2016, 05:07 PM
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Originally Posted by chris923 View Post
Dreamworks sells Hysol 9465 It works great for fuse former's and servo trays, pin hinges ect.......
just went to DreamWorks model products and I did not get a hit on Hysol 9465. Is that the right site?
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Old 03-08-2016, 05:25 PM
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Default redoing the bracket



I am thinking of redoing the brace get the screws out and start over.

I am thinking of roughing up the cockpit area, putting glass on it with 30 min. epoxy. Then put a layer of lite ply.

This will be the place where I mount the pilot and put in the switches for radio and on board glow. I would put in push pull power switches and make them look like part of the panel.

the underside would be another thing, I will look into another way of supporting the braces inside.
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Old 03-08-2016, 05:35 PM
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Originally Posted by Stick 40 View Post
not sure what you mean by Bent the fuse??

second question, if you have flown it how did it fly????
Bent, cracked, punch in, same difference. The problem that created that crash was the control sticks to the elevators buckled. I fixed it but it has sat idle while I am doing other projects.

http://www.dreamworksrc.com/catalog/Hysol-9462

You need to look under adhesives on the Dreamworks page.
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Old 03-10-2016, 06:59 PM
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went there, ordered it.

I am starting over, took the alum bracket out and going to redo it. will work on another plane for a few days.

thanks

sticks
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