oh...oh...got a more serious problem

[Capt. Crash]

It's cracked all the way through and I can make it open up by flexing it.

[Jeff Wohlt]

Should be a warranty issue. They will fix it or replace it. Call Hobbico.

[Capt. Crash]

Should be a warranty issue. They will fix it or replace it. Call Hobbico.

I posted this so ya'll can look out for the same thing on your boats...and to get some advice on how to fix it...if it can be fixed.

I already have a lot invested in this...paint, decals, modified the turn fin and I just added a kick plate for it. I also had to fix the water jacket and squeeze glue through the turn fin holes after I found that crack.

Ya'll think some thin CA would fix this new crack? I'd hate to box this thing up and send it back!

Is this something that these types of boats generally do...get stress cracks?

[Darin Jordan]

Is this something that these types of boats generally do...get stress cracks?

Sure... it happens... depends on the hull...

I kind of saw this as a potential problem, so if you follow my UL1 Race Prep thread, when I poured in the epoxy for the backing plate, I ran some down into this area as well. Basically filled it up completely. Just in case.

Perhaps a small hole on the other side and another pour in there may be in order... Guess I have another update to do!

[Grimracer]

holy schnikies... hum...

I have to do some flexing on my boats.. I have not seen this but it bothers me a bunch..
Dang ballance between a racer design and making it useable for the new guy too..

Hum

grim

[detox]

Remember everyone. Try to think it over and COOL OFF a couple of days before you make any comments.

HA HA









.........................

[Capt. Crash]

Just in case anyone is wondering...I have not dropped this boat or had it airborne or flipped it. It has run somewhere between 20-30 miles in mostly less than smooth conditions. I would call it simulated race water. (10-20mph winds and one side of the pond is walled) The boat has done what I call the "hospital hop" or violently wobbled from sponson to sponson, but I was always able to save it. I think that probably put the most stress on the hull and may be the culprit for causing the stress fracture.

I'm still reluctant to cut holes in the tub and will try some thin CA in the crack and see how it holds up. Darn rain won't let me get out today...hopefully tomorrow. I may even get brave enough to put on that 40X57 again...I never got it to hook up the first try....but now I know to lower it.

Will I need the air damn for that prop too or should it stay upright with out it?

Capt. Crash...the Montgomery Model Boat Club (MMBC) Guinea Pig!

[Grimracer]

capt..

Can you measure from the back of the sponsons to the break/s.. on both sides for me..

Thanks in advance

Grim

[egneg]

I checked my boat and it also is cracked in this area but on the same side as the turn fin. The crack is 22mm from the sponson and angles back to the sponson at about 45degrees for about 10mm on the inside and to the transition on the outside. Also there is a crack on the bottom of the sponson where the turn fin mounts. I have run the boat 3 times on fairly flat water using a Octura M445 and a Prather detongued and back cut 225s. Hope this helps.

[AndyKunz]

I answered this on your cross-post in RCG. The fix is easy. For those who haven't broken yet, check out Darin's thread.

Andy

[Capt. Crash]

It is only on the starboard side...so far. Let me know if i can be of further assistance.

Crash

[egneg]

I answered this on your cross-post in RCG. The fix is easy. For those who haven't broken yet, check out Darin's thread.

Andy

Will 30 min epoxy work as well as I haven't found 2 hour epoxy.

[Jeff Wohlt]

I do not see it as a design flaw from Grimracer I see it as a Manufact flaw from being to thin on the gelcoat but more inportantly the glass layup which flexes the gel coat and then it cracks.

Glass is much different in that area compared to ABS. It has to be built up there with more than the other parts of the glass hull.

I think it can be fixed easy enough if you like to do that stuff but if not AQ is well aware of the problem....as with the leaking cooling ring.

[Flying Scotsman]

Robert, thanks for the heads up. I am going to be busy little bee with the mods. Please note this is an RTR boat and for guys who have built boats from scratch or manufactured hulls only. These issues are annoying but fixable.
China has had some quality issues with some products but not all. A prudent distributor of products will sign off on production models at the manufacturer's plant. But that does not mean that all models will be built to design and sign off quality.

Douggie

[Grimracer]

You know what.. it looks like (depending on your batteries) that is close to the CG..

Here is what i suspect..

The boat lands in the water hundreds of time each run. it must be flexing from the weight + impact force at the CG.

Im going to see what can be done about adding extra cloth in that area.

WILD.. after 100s of runs on the development boats we never saw this... like taking a brick to the side of the head.. that one left a mark!

Are we OK with this suspicion and suggestion guys?

Grim

[JimClark]

Is it possible that there isn't cloth (or very little) in the air dam protrusion? it must be extremely hard to get cloth into the molds even in vacuum bagging it.

Jim

[AndyKunz]

Will 30 min epoxy work as well as I haven't found 2 hour epoxy.

I like to use 2 hour because it gives lots of working time and you want it to flow freely down into the gap and seal things up well.

You could try 30 minute and let us know.

Andy

[Capt. Crash]

Is it possible that there isn't cloth (or very little) in the air dam protrusion? it must be extremely hard to get cloth into the molds even in vacuum bagging it.

Jim

That is what I suggested on this post after the sponson sagged when I touched it and it was not that hot.

https://forums.offshoreelectrics.com/...ead.php?t=6221

Now with this crack too it makes me start questioning this whole adventure. It's starting to look like my whole boat needs strengthening. How much bulkhead adding/upgrading and glue do I need to pour into this to keep it together?

How much can I do to it before my warranty becomes void? How many holes can I put into it before it is unreturnable?

A replacement hull with the stuffing tube already installed is starting to look better. and better...but it needs to be completely upgraded and be a lot better than this one or it's a waste of my time and patience.


At this point I'm also considering the Proboat offering again...using the Miss Elam hull and everything else from this thing as a last resort. I really like this boat but I'm starting to lose my patience with it.

[SweetZ28]

You know what.. it looks like (depending on your batteries) that is close to the CG..

Here is what i suspect..

The boat lands in the water hundreds of time each run. it must be flexing from the weight + impact force at the CG.

Im going to see what can be done about adding extra cloth in that area.

WILD.. after 100s of runs on the development boats we never saw this... like taking a brick to the side of the head.. that one left a mark!

Are we OK with this suspicion and suggestion guys?

Grim

Also Grim keep in mind it's cold out and the water is much colder than in the summer time ...so you guy's may have been testing in warm waters and cold makes stuff tend to crack much more easy and you guy's had no way of knowing this because i bet it wont happen in summer time when water temps are much warmer?... this is what i am thinking

[JimClark]

I am not talking about the bottom only the small air trap just behind the sponson it would be next to impossible to get cloth down in the area where the crack has develpoed at the beginning of the thread

That is what I suggested on this post after the sponson sagged when I touched it and it was not that hot.

https://forums.offshoreelectrics.com/...ead.php?t=6221

Now with this crack too it makes me start questioning this whole adventure. It's starting to look like my whole boat needs strengthening. How much bulkhead adding/upgrading and glue do I need to pour into this to keep it together?

How much can I do to it before my warranty becomes void? How many holes can I put into it before it is unreturnable?

A replacement hull with the stuffing tube already installed is starting to look better. and better...but it needs to be completely upgraded and be a lot better than this one or it's a waste of my time and patience.


At this point I'm also considering the Proboat offering again...using the Miss Elam hull and everything else from this thing as a last resort. I really like this boat but I'm starting to lose my patience with it.

[Capt. Crash]

My sponson bottom sagged...and the topside hull area just forward of the vertical fins seems very flexible too. I can press on it and it flexes...more so on the starboard side. It seems very thin there. Add to that Grims question about the possible need for more glass in the tub under the batteries....where does it end? I measured the surface temps @ 51 degrees. Air temp 40-50.

[JimClark]

Dudes it is a race boat there are going to be areas that flex. If you made it rock solid with glass it would sink or at least not get up on a plane because of the weight

[Capt. Crash]

Dudes it is a race boat there are going to be areas that flex. If you made it rock solid with glass it would sink or at least not get up on a plane because of the weight

So you think a little epoxy down in that spot will fix it?

[JimClark]

flexing on the deck and some other areas is normal for a race boat. Now I don't have a UL-1 so maybe it is more flexing than I think but. The cracks are another issue.
Jim

[JimClark]

Where is the motor mount in relation to the cracks that are developing?
Just a thought it might not be a bad idea to stiffen that area in the tub some but I would wait until I hear from Mike Z on this as I am sure he is right on top of this issue.

Jim

So you think a little epoxy down in that spot will fix it?

[Steven Vaccaro]

Anyone see this. https://forums.offshoreelectrics.com/...ead.php?t=6308

[planezero]

It is only on the starboard side...so far. Let me know if i can be of further assistance.

Crash

Just checked my hull it has two cracks on the other side (where the fin is ) 5,5 and 6,5 cm from the point where you are measuring.
In my case its just the gel coating that has cracked. Not serious at all (yet ?).

For reference, I've only had about 8 runs on my boat, but the last one was a major crash at top speed with a fountain installation.

[Capt. Crash]

Anyone see this. https://forums.offshoreelectrics.com/...ead.php?t=6308

That may be the ticket...I don't want to keep adding weight to this thing try to fix the weak points.

I would like to ask some questions over there and registered last week but still have no posting rights. I can't figure out how to contact the admin. to see why I can't post. Would someone here send a heads up to him for me? I registered as Capt. Crash over there.

Thanks

[Grimracer]

under the batterys? What?

The batterys are in front of the CG...

O man...



Grim

[egneg]

under the batterys? What?

The batterys are in front of the CG...

O man...



Grim

No behind the sponson on the rail leading towards the back just like in the captains picture. It very well could be at the center of balance but I have taken everything out to make repairs so I can't check it.