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How to rectify bulkhead errors?


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Help, please.  I've started a log on my Armed Virginia Sloop, but it's taking time to write up and so I'm ahead of my log.

 

I've glued in (PVA) all the bulkheads, and added reinforcing blocks between them.  I thought I was being so careful, but managed to get a couple of them wrong. 

 

I hope these pics will show that bulkheads 5 and 7 (counting from the bow) have obviously been fitted with a tip from starboard to port, leaving them in on the starboard, and out on the port.

 

post-3616-0-91354700-1389164269_thumb.jpg

 

post-3616-0-77083600-1389164256_thumb.jpg

 

As you can see, the "timberheads" are very thin where I've made these errors.  I realise I can shim them, but, when I trim them back on the other edge the shim will be unsupported.

 

Is there some way to recover from this, or must I try to remove those two bulkheads somehow?

 

Thanks,

 

Brett

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What PVA glue is it? Surely some water can help loosen it?

 

Otherwise measure a line on the inside of the bulkhead where it should be and glue material to there and sand the outside to get the right shape for the bulwark and gunports, once those are in and it is a bit more structurally sound then you can fix the alignment below when you fair the hull shape (i,e sand it). The side that is lower than it should be can have some thin wood strips to thicken them? That is provided the false keel is dead straight.

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Thanks, guys.  I forget that these constructions get stronger as you add bits.  I persist in thinking of each part as a stand-alone!

 

Demonborger, I use several - WeldBond, Selleys, Parfix - depends which one I grab.  They seem chemically similar, and, once set, don't soften in water quickly.  And, of course, I don't want to soak the whole thing.

 

Mark, I tried the isopropyl alcohol on my first model, but it did not release the PVA I was using.  Maybe there are different formulations.  I've seen references to yellow coloured PVA from the USA, but here in Australia they are all white.

 

Thanks all - I'm happer now than I was an hour ago!

 

Cheers,

 

Brett

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Along the same topic.... what is a good way to test the fairness of frames?  I am building HMS Bounty with open frames and I can sense that they are not all going to lay in perfectly fair for planking.  I have glued in 7 of the total 15 frames, added the lower deck support beams, and am ready to put in the lower forward deck.  I laid a strip of paper from station (frame) 4 back to 10, and I see that planks won't lay up against station 8 as they should.  I am conjuring up laying on a piece of thin wood (probably some excess deck planks) to build up that side.  Interestingly though the opposite side does not have as great a reverse problem.  I think sanding will take care of any excess material on that frame.  Before I move on to add the aft 8 frames, is there a tried and true technique for positioning these (rather flexible) frames so that a good degree of fairness is achieved?  Like Brett who started this forum I thought I was taking as much care as possible.  Used perfectly square braces at the false keel joints, measured to the mm the distances between frames, etc. etc. but still got this one (and maybe others) a bit off.  Is it possible that with the addition of accurately cut beams (for all 3 decks) that what now looks and feels like a frame is out of line, may right itself?  I am going to attach a photo, but don't know if I do that correctly. 

post-9306-0-02937100-1389200268_thumb.jpg

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the yellow glue is probably Titebond.

 

Brett, some modellers from different countries don't know what pva is. Probably best to call it white carpenters wood glue. 

 

 

Hi Brian,

 

The thread on preferred glues mentions PVA often - from members in several countries.  I reckon we've learned 'em to speak proper!

 

My personal difficulty was seeing "CA" in threads, and interpreting it as "Contact Adhesive"!!!  Whoops.

 

I've decided to have a shot at un-gluing my errors.  I'll try softening some with water, and some with IPA (isopropyl alcohol) - love those TLAs (three letter acronyms)!

 

I will report back, unless I wreck the model.

 

Cheers,

 

Brett

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If it's carpenter's glue (yellow or white) then it's most likely PVA and alcohol will usually release it.  Sometimes water.  But water can distort the wood.

 

If it's school glue or paper glue, then water will usually do the trick.

 

If it's CA (not contact adhesive), then acetone will work.

 

Rubber cement... acetone.

 

Some people have found heat from a hair dryer or heat gun (Caution!!!!) will also break the bond.

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Along the same topic.... what is a good way to test the fairness of frames?  I am building HMS Bounty with open frames and I can sense that they are not all going to lay in perfectly fair for planking.  I have glued in 7 of the total 15 frames, added the lower deck support beams, and am ready to put in the lower forward deck.  I laid a strip of paper from station (frame) 4 back to 10, and I see that planks won't lay up against station 8 as they should.  I am conjuring up laying on a piece of thin wood (probably some excess deck planks) to build up that side.  Interestingly though the opposite side does not have as great a reverse problem.  I think sanding will take care of any excess material on that frame.  Before I move on to add the aft 8 frames, is there a tried and true technique for positioning these (rather flexible) frames so that a good degree of fairness is achieved?  Like Brett who started this forum I thought I was taking as much care as possible.  Used perfectly square braces at the false keel joints, measured to the mm the distances between frames, etc. etc. but still got this one (and maybe others) a bit off.  Is it possible that with the addition of accurately cut beams (for all 3 decks) that what now looks and feels like a frame is out of line, may right itself?  I am going to attach a photo, but don't know if I do that correctly. 

 

Al, I built the same model several years ago and had the same issue with a few of the frames. They aren't cut as accurately as they could be, there are slight variations in the centre notches and some are not quite the correct shape.

 

It's no big deal, once you fit the upper deck "stringers" (I suggest you do this temporarily now - see below) you can align them a bit better. Once you are satisfied that the frames are as close to aligned as they are going to get you can then fair the hull. This will remove any high points - sand them down to the lowest points.

 

You can glue the stringers in temporarily using white PVA glue. If they need to be removed again (for some reason that I can't remember) you can de-bond them using Isopropyl Alcohol (aka "Rubbing Alcohol", available at pharmacies or some supermarkets).

 

Another tip for the open side of this model - use some walnut veneer (thin planking strips) to line the edges of the frames to hide the unsightly plywood edge. I wish I'd done that with mine instead of trying to just stain the edge - it would have improved it greatly. Soak the veneer in water for a couple of minutes, clamp to the frames and allow it to dry thoroughly, remove the clamps and glue the strip on with PVA, allow to dry and then trim it to shape by sanding the edges of the veneer.

 

:cheers:  Danny

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Hi

I had  similer issues - i was able to fix it by adding extra  wood to the frame but as I was double planking it was well coverd

- it all depends on if you whish to start pulling apart the work you have completed so far or the finiish you require on the planking intend.

 - (its all an education nomatter how expensive a hobby)

Kerry

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Some good info here on rectification of the problem. It would be good though if one of you more experienced guys could possibly do a tutorial specifically on how to avoid the problem in the first place. It's a big ask but worth mentioning maybe?!

Edited by Q A's Revenge
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Well, as I said, I tried un-gluing.  Both the water and the isopropyl alcohol allowed me to remove the stiffening blocks, but with difficulty.

 

The water tended to swell and warp the basswood.  Before I jumped in, I tested this on some scraps.  After 1 hour soaking, the samples pieces swelled by approx 8-9%.  However, after 2 days air drying they were back to within 1-2% of their original size.

 

The alcohol is hard to use - I tried to keep the joints soaking for an hour, but it evaporates quickly in our 30-33C weather!

 

With both methods I had to apply more force to remove the blocks than I liked, but they came loose.

 

Adjusting the bulkhead, well that was scary, and near impossible.  I could not (dared not) free the bulkhead, so I twisted it a little in situ.  The water soaking allowed this for the first one I tried, but alcohol on the second one was less successful.

 

End result - a lot of time and stress for little result.  I should have listened to the folk who said shim & sand!

 

BTW when you look down the deck it is easy to see where my initial positioning was wrong.  In this photo I have already worked on the 8th bulkhead - the one with the faint blue mark on the right (sorry - port in this view!).  The darker blue marked bulkhead (6th from the near view) cants up on the right, and was next to be adjusted:

 

post-3616-0-74974400-1389682377_thumb.jpg

 

Here is the view after removal of the first blocks:

 

post-3616-0-02284100-1389682605_thumb.jpg

 

Fortunately through all this I had one of my trusty assistants protecting my chair wheels:

 

post-3616-0-89804200-1389682685_thumb.jpg

 

Thanks for all the help - I will now continue in the build log.

 

Cheers,

 

Brett

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Hi Brett,

 

Sorry, forgot to mention a little tip about using Alcohol on large/difficult joints like you had. Some Stretch Wrap put around the joint after applying the alcohol will slow down the evaporation rate. Several applications may be necessary on some joints.

 

Something to remember if you need to do so again in the future.

 

:cheers:  Danny

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I had a similar problem which I solved by sawing out the blocks, debonding the joint at the keel, then regluing that joint and installing new blocks between the bulkheads.  Other fixes were made by gluing on more material per prior posts above.

 

Remember, wood is wonderful and can be easily shaped.  Some parts, like deck furniture, are exposed to close scrutiny so would need to be remade, not repaired.  

 

Persevere and have fun.                                 Duff

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  • 4 weeks later...

Dan, I should have replied weeks ago but personal circumstances have prevented me from paying much attention to my hobby. But I did want to thank you for providing insight into the imperfections of some of the pieces provided by Art. Latina's kit. I presume that there are very few kit manufacturers that are absolutely perfect and I've come to learn that finding their imperfections before using any particular part is part of the task of modeling. It is comforting to know though that there are not too difficult ways of remedying situations, and that not all the imperfections in my build are my fault. When I am finished with Bounty (which could be a long while) and looking for another kit, I will raise a topic discussing which manufacturers are better than others and which should be avoided.

 

Capt. AL (I see I need to be careful when abbreviating the name of Artesania Latina lest readers think I am referring to myself).

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  • 2 weeks later...

Greetings, 

 

This is an interesting thread for me because, as a supplier of kits, I see this problem, as well as other similar problems regularly and I'm working on what might be a solution. 

 

My impression is that builders would be very interested in getting a complete, CAD designed, laser-cut set of keel, bulkhead and deck pieces based on their line drawings. 

 

Some of the top quality kits I sell do have laser-cut parts although I'm not sure how the parts were originally designed. On the other hand, most of the commercial brands I sell have hand-cut bulkheads that are made with poor quality wood and that are not symmetrical or sized properly. 

 

Good bulkheads would help people get through this part of their models faster and more accurately. All this would translate into more fun and more models getting built. 

 

Comments? 

 

Best Regards,

 

Rick Shousha

Montreal 

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Hi Rick,

 

I'm only on my second model so don't take my opinion for much.

 

On my first model, precise cut parts would have been wonderful.  However, now I look on the discrepancies as part of the fun of model making - after I realised you can unglue, sand down, or shim.

 

Given that many models take a year or more, I don't think speed is a concern.

 

Maybe for the first-timer or modellers in a hurry this would be attractive?

 

Cheers,

 

Brett

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Hi Rick,

 

For a First Timer good instructions, tips on hull fairing etc would be more beneficial than laser-accurate cut bulkheads. Information like this, rarely supplied in a lot of kits, would give a Newbie the grounding needed to make a good job using the poorer quality material of the lower range kits out there.

 

I'm not saying that laser-cutting isn't a good idea (which it certainly is), just that the cost of a couple of hours worth of typing/illustrating good instructions would be more worthwhile in the long run.

 

:cheers:  Danny

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I have had a similar issue. PVA glue can be softened and the bulkheads either removed or adjusted. Just use a hair dryer on high heat and apply it for a few minutes. The glue, which is just a plastic base, will soften and you can move the parts.

 

Vince P.

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