DRAGONFLY Trimarans User Forum

I have a small series of cracks around the base of the spray hood pivot on the starboard side of the cockpit, I asumed that this was just cracking in the gel but when sailing in just 15 kns of wind these cracks are opening and moveing, NOW I am worried if this area is a strss area then I could have a major hull failure!!!! I am disapointed to say that Jens has not responded to my email on this in 3 months ( how busy is he ? )

So do I just get the gel repaid or do I need to reinforce this area and if so how ?
If anyone feels thay can help
i/will email a photo

good sailing

buckle.roger wrote:I have a small series of cracks around the base of the spray hood pivot on the starboard side of the cockpit, I asumed that this was just cracking in the gel but when sailing in just 15 kns of wind these cracks are opening and moveing, NOW I am worried if this area is a strss area then I could have a major hull failure!!!! I am disapointed to say that Jens has not responded to my email on this in 3 months ( how busy is he ? )

So do I just get the gel repaid or do I need to reinforce this area and if so how ?
If anyone feels thay can help
i/will email a photo

good sailing

Hi Roger
Sounds like a bad thing. One possibility to find out is this a real problem is to paint the cracks with nail polish, and go out for sailing. If the nail polish layer brokes you know these cracks are in area with high loads (I think you know this already). I do not know the exact structure of DF920, so I cant help you more. Anyhow my opinion is you need to repair this problem before something more serious damage exists.

Rodger:
The one good thing to remember about a fiberglass boat is that it is basically easy to repair. You have to identify what is causing the problem and why is it flexing. If your not comfortable doing your own fiberglass work, I am sure there is someone around your marina that can give you some guidance.

A good place to start on line is with West System Epoxy. Do a search for that. They have on their web site how to repair anything. I am not sure if that product is available in Europe, but if it is not, I am sure you can find something that is equal.

Understand what is damaged, cut it out with a Roto-zip tool or equilivant. Reinforce the inside with glass mat. Epoxy over, little bit of gel coat or paint and your as good as new.

Fiberglass repair work can be scary to the uninformed, but once you learn the basics, it is real easy. Do your research, spend your time to do your prep, have a plan and follow it. Make sure you read and follow the directions and you won't go wrong. If it comes out a little rough.. the good thing is it sands out smoothly.

Sorry that might not have been the answer you were looking for but I hope it gave you enough encouragement that you can do it.

Ted

Mika Harju wrote:
buckle.roger wrote:I have a small series of cracks around the base of the spray hood pivot on the starboard side of the cockpit, I asumed that this was just cracking in the gel but when sailing in just 15 kns of wind these cracks are opening and moveing, NOW I am worried if this area is a strss area then I could have a major hull failure!!!! I am disapointed to say that Jens has not responded to my email on this in 3 months ( how busy is he ? )

So do I just get the gel repaid or do I need to reinforce this area and if so how ?
If anyone feels thay can help
i/will email a photo

good sailing
Hi Roger
Sounds like a bad thing. One possibility to find out is this a real problem is to paint the cracks with nail polish, and go out for sailing. If the nail polish layer brokes you know these cracks are in area with high loads (I think you know this already). I do not know the exact structure of DF920, so I cant help you more. Anyhow my opinion is you need to repair this problem before something more serious damage exists.[/quot

Thanks Mika for the responce. What I need to know is how much reenforceing my be needed, as I has said this crack does more when sailing, It is ver disapointing that the fctory will not respond to this, I do'nt think they would like to hear of a 920 with a major hull fault ??]

[quote="tpaliwoda"]Rodger:
The one good thing to remember about a fiberglass boat is that it is basically easy to repair. You have to identify what is causing the problem and why is it flexing. If your not comfortable doing your own fiberglass work, I am sure there is someone around your marina that can give you some guidance.

A good place to start on line is with West System Epoxy. Do a search for that. They have on their web site how to repair anything. I am not sure if that product is available in Europe, but if it is not, I am sure you can find something that is equal.

Understand what is damaged, cut it out with a Roto-zip tool or equilivant. Reinforce the inside with glass mat. Epoxy over, little bit of gel coat or paint and your as good as new.

Fiberglass repair work can be scary to the uninformed, but once you learn the basics, it is real easy. Do your research, spend your time to do your prep, have a plan and follow it. Make sure you read and follow the directions and you won't go wrong. If it comes out a little rough.. the good thing is it sands out smoothly.

Sorry that might not have been the answer you were looking for but I hope it gave you enough encouragement that you can do it.

Ted[/qu

Hi Ted
Thanks for the responce, I will get someone to do this. Rough GRP work I am ok at but not gel work, problem is I think it means cuting the side of the cockpit to get under the cracked area , question is why did it crack too?

All the best

roger

Rodger:
Just one further point of information. I believe there are two steel bands that are located in the main hull. One is located in an approximate location of the forward cross beams, and the second is located in the vicinity of the aft cross beam. If that crack is in the vicinity of the aft cross beam...be real careful - who ever is doing the repair- If you cut these bands that would be, from what I've heard, unrepairable.
I know the 800's were constructed in this manner, and I know of one boat that is no longer because of this.
I have to think that all the boats are pretty much similar in their basic design to some degree.
Ted

I don't think the part of the deck where the spray hood pivot point is mounted is a particularly high stress area. However, this is a favorite spot to step on when rigging/de-rigging at the beginning and end of season, or even when taking sails down or closing sail cover. I think the spot was damaged accidentally when something heavy (mast) fell on that ridge or someone sliped in a heavy boot and damaged the base mount.

Remove the pivot point base and inspect the area. You may find evidence of prior damage or more likely you will find that the screws became loose and are working the hole and the cracks in wind-induced dodger movement.

If it is the latter, just fill the holes and the cracks with epoxy; let it cure; then re-drill the holes and re-mount the base. If it is the former, have a professional re-glass the area.

As far as I know, there is nothing in that space inside.

gminkovsky wrote:I don't think the part of the deck where the spray hood pivot point is mounted is a particularly high stress area. However, this is a favorite spot to step on when rigging/de-rigging at the beginning and end of season, or even when taking sails down or closing sail cover. I think the spot was damaged accidentally when something heavy (mast) fell on that ridge or someone sliped in a heavy boot and damaged the base mount.

Remove the pivot point base and inspect the area. You may find evidence of prior damage or more likely you will find that the screws became loose and are working the hole and the cracks in wind-induced dodger movement.

If it is the latter, just fill the holes and the cracks with epoxy; let it cure; then re-drill the holes and re-mount the base. If it is the former, have a professional re-glass the area.

As far as I know, there is nothing in that space inside.

Hi and thanks for your thoughts , I hope you are correct and it is not a stress area, The face that the crack moves when sailing does worry me a little though, I guess as it is very difficuly to get at a good start would be to grind out the gel and make good and see if the cracks come back.

Fiberglas is flexible. Find out what is moving it when sailing.... is it the spray hood? Most likely. Is there someone who likes to hold on to it really hard?

So, most likely some reinforcement will do the trick and your hull is not about to disintegrate. The easiest way to do it would be to get to the inside and build up a few layers of glass/epoxy. Then do a subtle gelcoat crack repair on the outside.

Unfortunately I am not familiar enough with the boat to evaluate how easy it is to get to the inside.

Oscar wrote:Fiberglas is flexible. Find out what is moving it when sailing.... is it the spray hood? Most likely. Is there someone who likes to hold on to it really hard?

So, most likely some reinforcement will do the trick and your hull is not about to disintegrate. The easiest way to do it would be to get to the inside and build up a few layers of glass/epoxy. Then do a subtle gelcoat crack repair on the outside.

Unfortunately I am not familiar enough with the boat to evaluate how easy it is to get to the inside.

Hi

Thank you for your thoughts.
I am starting to understand the stresses better, When unfolding the starboard ama ( on my mooring ) when it is almost full open with some tension then the crack at the base of the spray hood fitting opens a little. This then IS a high stress area. the problem is getting access to the inside to strengthen it.it may have to be done on the outside?????

You won't do any substantial reinforcement on the outside without aesthetic implications.... (translation=without seeing it).

But, if it is indeed that structural a more in depth evaluation of what's going on is needed. There may be something amiss. I would up the urgency on your com with Q. Squeaky wheels and all that.......

[quote="Oscar"]You won't do any substantial reinforcement on the outside without aesthetic implications.... (translation=without seeing it).

But, if it is indeed that structural a more in depth evaluation of what's going on is needed. There may be something amiss. I would up the urgency on your com with Q. Squeaky wheels and all that.......[/quote

Hi again

I agree it needs a factory recomended fix but as yet I am haveing no luck from the factory ????????? I hope to here something useful very soon !!]

Get SKYPE and start ringing and ringing and ringing..........

Oscar wrote:Get SKYPE and start ringing and ringing and ringing..........

Good point

buckle.roger wrote:I have a small series of cracks around the base of the spray hood pivot on the starboard side of the cockpit, I asumed that this was just cracking in the gel but when sailing in just 15 kns of wind these cracks are opening and moveing, NOW I am worried if this area is a strss area then I could have a major hull failure!!!! I am disapointed to say that Jens has not responded to my email on this in 3 months ( how busy is he ? )

So do I just get the gel repaid or do I need to reinforce this area and if so how ?
If anyone feels thay can help
i/will email a photo

good sailing

Roger -
Can you post some detailed photos of the crack you are describing? We're all just guessing without that information.

Also -- in general, epoxy is not the best repair material for a polyester fiberglass boat like a Dragonfly. It has the advantage of being low-odor and epoxy provides a superior secondary bond strength compared with polyester, but it is stiffer and does not provide a good base for polyester gelcoat finishing. Epoxy should be painted, although people claim they have been able to get gelcoat to adhere it is not so certain. An epoxy repair will also create a "hard spot" that over time may cause failure near the edges of the repair, as the boat flexes repeatedly.

I have done research on this: The best repair material for a high-stress area on a Dragonfly (or any polyester boat) is vinyl-ester. I have an email from Jens Quorning agreeing with that.

Vinyl-ester (or may be spelled vinyl ester or vinylester) is almost as strong for secondary bond strength as epoxy, and is compatible with polyester gelcoat matching the factory finish. It flexes at about the same rate as polyester. If the repair is not in a high-stress area I would use polyester resin, for compatibility reasons. Epoxy would be my third choice.

buckle.roger wrote:(snip) I am disapointed to say that Jens has not responded to my email on this in 3 months ( how busy is he ? )

So do I just get the gel repaid or do I need to reinforce this area and if so how ?
If anyone feels thay can help
i/will email a photo

good sailing

One other thing --
I also suggest you email detailed photos to them so they have something to look at, and follow up your email with a phone call. You can't expect good detailed answers without providing good detailed information.

Double Horizon wrote:
buckle.roger wrote:(snip) I am disapointed to say that Jens has not responded to my email on this in 3 months ( how busy is he ? )

So do I just get the gel repaid or do I need to reinforce this area and if so how ?
If anyone feels thay can help
i/will email a photo

good sailing
One other thing --
I also suggest you email detailed photos to them so they have something to look at, and follow up your email with a phone call. You can't expect good detailed answers without providing good detailed information.

Hi guys

thanks for all comments, I have managed to get a call into Jens ( I had sent him photos ) He was most helpfull, It seems though this problem has not been seen on a 920 touring but it has on the extreme, as I was putting very high winch loads on both outhaul lines and backstays when I first sailed the boat I guess the stresses could have been similar.
It seems this area is not a high stress area but it is a area were the hull flexes, The fix has to be on the outside as it is not possible to get at from inside, So 7 layers over the edge that the spray hood is fastened to is the answer.

good sailing

roger

Ouch......

Better start reading up on fiberglass work....

Oscar wrote:Ouch......

Better start reading up on fiberglass work....

Ouch indeed

I did better than read up I got a pro to do it and the problem came to light. as he ground out around the cracking there were holes down the line of the crack which were just filled with filler, no gpr so this corner has been very weak and hence the crack.

~hopeful this now resolves this . I will find out when we have some wind

good sailing

there were holes down the line of the crack which were just filled with filler

The holes were there to stop the crack from growing. I've seen aircraft mechanics do the same.

Oscar wrote:
there were holes down the line of the crack which were just filled with filler
The holes were there to stop the crack from growing. I've seen aircraft mechanics do the same.

Hi you are quite right drilling a hole at the bottom of any crack will help stop it going further by spreading the load around the hole rarther than in one very small spot as in a crack, However in this case the holes are better described as voids not nice round holes, there were several of them dowm the line of the cracking and were filled with filler.Simply a maufacturing problem.

The fix was not as bad as I thought but the real test will be a fast sail in a good wind, heres hopeing

DRAGONFLY Trimarans User Forum

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