U-91035 "PROTEUS": Hull issue........

[trout]

I am betting you will make it work! (but, boy are you going to pay for it)

[QuarterMaster]

Okay folks.....

The scary part is that she does fit, at least the section that needs repair.

So I have to.....
1-Give the Admiral a credit card and send her to the mall* The less she knows, the better. (I once heard HWSNBN say it's better to beg forgiveness than beg permission)
2-Plan out the sequence of events.
3-Wear my pigskin gloves
4-Monitor the hull temp closely with the IR thermometer.

I plan to do it this weekend.
Epic save or Epic disaster.....Bob will take cash for the betting.


*Either way it's gonna frakking cost me

[QuarterMaster]

Hi Ed
you could try too fix her by securing the hull too the table and put blocks or jacking under each nacel slightly higher target height too allow for some spring back when heating and cooling thermal cycling is complete..............,.,.....
i believe the hull is polyester, these hulls were done with a chop gun from what I recall.

I'm going with the heat method, see below.

[QuarterMaster]

Is the top showing the same amount of warp?

No.... she's fine there. I did cut the hull as you did, so I'm worried that section WILL warp when epoxied together. Hence the need to repair now.

[QuarterMaster]

I did a YouTube Live talk on this a while ago: https://youtu.be/iAind7AKT50, and talk about fiberglass specifically at this point: https://youtu.be/iAind7AKT50?t=445.

It was one I missed, sat down and watched it.
Understand temp I would want is 200°F as a target.

Thanks Bob!

[Rick Teskey]

Hi Ed
you could try too fix her by securing the hull too the table and put blocks or jacking under each nacel slightly higher target height too allow for some spring back when heating and cooling thermal cycling is complete or make radial slits inside nacel too make it flexible like an accordion, then reglass. Or combine both methods by cutting slight radii, blocking up too height and reheat and fill cuts.
i believe the hull is polyester, these hulls were done with a chop gun from what I recall.
if you go with cut and fill lay a waxed pipe in the channel for a smooth contour.

[Rick Teskey]

Is the top showing the same amount of warp?

[QuarterMaster]

Hmmmmmm.........
Well, it's gonna save me from walking back to the Circuit Card Assmbly area here at DDC to beg a favor allowing me to run PROTEUS through the SMD oven at 135c!!

[Subculture]

This sort of thing tends to happen if the moulds are a bit green when pulled from the tool. I've found epoxy resin is more amenable to being reworked with heat than polyester, the latter is what I'm guessing you have there. I think the clamp and cure is probably the way to go. Wouldn't be afraid to cut the hull either if necessary, the proteus will be easy to rework, as it's a smooth undeleted hull and it looks like you have plenty of meat on the bones to sand back to profile.

[RCSubGuy]

I did a YouTube Live talk on this a while ago: https://youtu.be/iAind7AKT50, and talk about fiberglass specifically at this point: https://youtu.be/iAind7AKT50?t=445.

The general consensus amongst professional fiberglassers is that once the 'glass is fully cured, large adjustments to its form is not possible. Now, I've successfully done so in the past, even with older hulls, so that may not be entirely true.

Looking at your pictures, I think you could/should simply rough up the mating surfaces, epoxy them together and clamp it until fully cured. From there, work out your final access methodology, ensuring that opening it up won't create a structural weakness that will allow the hull to warp again.

If the "stock" hull split is what you want/need, then as Dave said, heat it up, clamp it and hope for the best!


Bob

[He Who Shall Not Be Named]

Heat-gun is your best (only) option.

David

[QuarterMaster]

Dave, Bob, et al,

Proceeding at a "Full" bell on this build, an issue I feared arose after all.

In test fitting the propulsion units, I discovered the hull has become warped after sitting all those years in the shed since I removed Rick's original flashing. If memory serves, you either own one of these Dave, or had seen it.

It's about a 1/4" to port, and a 1/2" or so on the starboard wing "gunwale" (for lack of a better term).





I know anything can be fixed, especially with 'glass, but suggestions from all ya'all (yep, a New Yorkah said it) out there would be much appreciated.

My first thought is lay it flat side down on a stable surface (thick board), use sheet metal stock screwed down overlapping the edges making it flat.

Stick the whole thing in a large enough oven set below the transition temperature of the glass, let it sit and hope for the best.

However......

1-I ain't got a large enough oven lol

2-I'm not sure what temperature I would even set it at, much less for how long to let it sit in one. Obviously I wouldn't want to yank out a sagging mess.


So, how is it really done? You saw late last year I attempted to fix 591's hull with a jig, heat gun and an IR thermometer.
Not sure how well it worked as it seems to be getting back to what it was. I was afraid to scorch the finish, bubble the glass, or even de-laminate it. So I went with a light touch...maybe 160° F as read by the thermometer, then quickly clamped it. Say a minute or so the it would cool naturally.

Any ideas?

Find someplace with a large, industrial oven that heats non-food items for a fee? (Doubt Ray's Pizza on 33rd and 3rd will do it)
Use the heat gun? (Recommended technique?)
Use one of Elon Musk's "BORING" Flamethrowers?

For you Dave, I'll even take a trip to SC and lower it into the Daniel Webster (MTS 626) reactor compartment if that'll do it.