Deck separation from hull

[Szubi]

This is my first post on this site, so hello everyone!

I’m Szubi and I’m an architect coming out of my long lego dark ages... yay! :)

And I come looking for help. 

Quick context;

Seeing some of the successes I’ve been having with retrobrighting recently bought vintage sets, my friend has asked me to retrobright a ship hull deck for him. Whereas the police boat 4010 was easy as it only needed pouring hydrogen peroxide into the hull to cover the deck, his fire boat 4031 is difficult in that it is a stepped deck design, it is much larger and it’s… red.
A color which will be affected by hydrogen peroxide, unlike the black hull of 4010. So, pouring hydrogen peroxide into the hull as well as partial submersion are really out of the question… I think.

Here’s the Question;

Has anyone attempted separating the gray decks from the hull?

It seems to be either glued in or snap-locked in. I’m really hoping that it is only snap-locked. 

I tried delicately prying the hull sides being very careful not to damage the hull or give it stress marks, to see the fixing method, but can’t see anything.

Thanks in advance for any input!

[Stuartn]

I am not fully sure as I don't have that set, but I know newer hulls are just snap locked and come apart easily. Some old pirate set hulls were screwed together but from what I have seen of the part you are referring to those hulls are not screwed. 

I would suggest getting a red brick from the set and submerging it in hydrogen peroxide first, to see if it does actually impact it and if it does to what extent. If it doesn't impact it too badly, you may be able to submerge the hull.

You could use a solution like Maskol to cover the parts of the hull that are visible and will come into contact with hydrogen peroxide to protect it when it is being retrobrighted

Edited May 19, 2021 by Stuartn

[Szubi]

Definitely no screws there... I really do wish it was that easy though.

Thinking this over, I am probably going to try and tape up the red hull and submerge the whole thing or part of it in the hope that H2O2 needs UV and hear to work.

Take one away (taped up surface > less H2O2 and UV) and it won't be affected.

I would prefer to have the decks come off somehow - it would make managing the liquid in a container + pieces that much easier.

[Jetflap]

So funny to read your post, just 2 days ago I successfully treated the red boat hull from 4020, also a stepped up design. I simply used a piece of duck (duct) tape around the inside rim of the hull, trimming it slightly at the stepped-up part to fit. Then filled the boat like you did with 4010, duck tape is water tight at least long enough for this process, it worked like a charm. Peroxide did not affect the red hull at all, it came out perfect, i wished I'd snapped some photos. Also, I thought the tape might leave some reside I'd have to clean off, but it pealed off clean. Whatever you do, do not try to remove the gray parts from the hull, they will be damaged in the process!

[Szubi]

Likewise, it’s funny to read that we came to the same conclusions. I taped up the entire hull, inside and out with electrical tape as it is easily formed around some of the bends and curves. I then extended the sides a little upwards and I poured H2O2 inside the hull and stuck the whole thing in the oven at 40’C for two days with the (incandescent) light on. So far this seems to be doing the trick. 
to minimize the amount of H2O2 used, I put two small jars inside the hull so the level of liquid went up covering the top/front deck nicely. I would agree from previous attempts at prying the hull sides away that the decks are in there for good, so is it’s better to leave them there. 

Edited May 23, 2021 by Szubi

[Szubi]

Well…

KIDS, DON’T TRY THIS AT HOME!

After two days at 40’C and soft light, I just peeled the tape and to my horror and dismay the red plastic faded badly in odd places - especially where the tape let go likely from warm and H2O2.

The gray came out beautifully though… :(

I now owe my friend a red boat hull.

So… gray, white, some blacks; OK

Red, blue, yellow; be careful  they will probably fade.

 

[SD100]

Well if the hull is that screwed up, would it now be feasible to try and detach the hull pieces to see if there is a way to do that?

SD

[Stuartn]

8 hours ago, Szubi said:

Well…

KIDS, DON’T TRY THIS AT HOME!

After two days at 40’C and soft light, I just peeled the tape and to my horror and dismay the red plastic faded badly in odd places - especially where the tape let go likely from warm and H2O2.

The gray came out beautifully though… :(

I now owe my friend a red boat hull.

So… gray, white, some blacks; OK

Red, blue, yellow; be careful  they will probably fade.

 

Would it be possible to 'repair' the hull with some sort of modelling paint, it might not be perfect but could salvage (pun not intended) the hull and make it usable at least for general MOCing.

Unfortunately most versions on Bricklink of this hull piece seem to have the same greying issue. I suppose this hull piece could be a good opportunity to experiment with new techniques for retrobrighting coloured Lego.

[Szubi]

Agreed; the plan now is to firstly get my friend’s set back to original by buying a new hull, one that hopefully isn’t as yellowed on the deck as his was. It was his childhood original set so I’m keen to give him an undamaged piece back. After all, I need to deliver on a promise, so I hope it is a fair deal; better deck, unoriginal (to him) hull. 

As for the damaged one; i am really curious to see the way it was assembled in the factory, but it is still in one piece so rather than destroying it completely, I think I will indeed spray paint it with a matching color and go for a vintage correct MOC, design wise.

Also, I did try to use a technique where heating up the plastic brings back the oils within for a new like look, much like on car door trim, but that didn’t work. The plastic is not the same though also ABS… I think.

Before I do a new paint job, I’ll go ahead and see if it can be polished. Some plastics ale good for this to bring back color.

Still. I’m really saddened to see this damage. It annoys me to no end. 

[Jetflap]

Sorry it didn't go well, I have had good success where I live. With our intense sun and high altitude, I can turn significantly yellowed parts to like new in just a couple hours! I have never had an issue with fading of colored parts. Never heard or thought of doing it in an oven, I can't imagine a light bulb in an oven being enough to cause much effect and obviously as you found out 2 days in H2O2 is much too long! Also curious why the oven? not sure that heat would help? I do mine outside in the dead of winter (below freezing) and it only takes slightly longer although I attribute that to the sun not getting as high in the sky.