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[StrayGull]

I’m currently building a Lightning wooden sailboat model. This is my first time building a model of this sort, and for my grandson, who’s building the same model in step with my build, it’s his first time ever working with tools and his hands. Needless to say, we could use a little advice from time to time. I’m hoping this will be the last post needed to qualify me to post images. I will follow this post shortly with another post including pictures and my pressing question of the moment.


Has anyone out there previously built the Lighting model put out by Dumas?

[StrayGull]

Here is where I am now. I’m hoping someone out there has actually built this same model, and can discuss the next step in this build, which I gluing the second bottom panel. I’ve already glued the first of these two panels, but gluing the second panel involves problems that aren’t present when gluing the first one.


Before I attempt to explain my problem, first let me ask if this is the correct forum for these kinds of questions?

[StrayGull]

Well, I’ve tried posting images with no luck. When tapping “Add image to post”, another webpage opens, apparently on a different website. After I select a couple of images, I’m returned to the Mayhem page, and my in-progress post, but the images aren’t shown. What am I doing wrong?

[dougal99]

Take a look here for posting pics https://www.modelboatmayhem.co.uk/forum/index.php/topic,61103.0.html

[StrayGull]

Thanks much, dougal99! Out of time right now. Will come back soon to review link you sent, and get a couple of images posted. 

[StrayGull]

I have fitted and glued the first bottom panel, and have fitted the second bottom panel, but have not yet glued it. The concerns I have about gluing the second panel are about two points. First, while the frame was assembled using good old, white, slow setting wood glue, Dumas states the panels should be glued using “gap filling, medium CA glue.”


I want to confirm these two images will successfully post this time, so I’m posting at this point, and will continue explaining my questions in the following post. Here goes!

[StrayGull]

Picture posting SUCCESS! 


So, to continue, I was explaining why I’m apprehensive about gluing the second bottom panel. As I was saying, the manufacturer of the model calls for the bottom panels to be glued with “gap-filling, medium CA glue.” When considering how the contours of the panels change as they are bent to conform to the curves of the hull, gluing them with CA glue becomes extremely challenging (at least to me.) Bending and positioning them in the exact correct position isn’t a quick, drop right into place sort of deal, and the CA glue means the panels stick in position pretty much instantly upon touching the CA glue spread on the frame!


I accomplished this successfully, with the first panel, by carefully dry-fitting the panel, as I thoroughly clamped it into place with a lot of clamps. Again, even with a dry-fit, considering how the panel effectively changes shape as it is bent to the curves of the hull, positioning it exactly (which is absolutely necessary) requires a bit of fussing around with it. However, after getting the first panel perfectly positioned and well clamped during dry fitting, I was able to then selectively remove clamps from one portion of the panel, allowing it to spring back to its flat shape, apply CA glue under that portion, then reclamp the portion, which returned to its exact correct position as it bent back to the shape of the hull, because the panel’s correct position had been maintained by the portion of the panel which had remained clamped. Then after that first-half glue-up set, I removed clamps from the portion of the panel which still wasn’t glued, its position now being maintained by the first part of the panel that was already glued. Finishing the second part of the glue-up and reclamping of the first panel was now a snap. Panel one, perfect!


Unfortunately, I can’t follow this same process with the second panel, as I’ll explain in my next post.

[StrayGull]

So, while the first challenge for me in gluing these panels, arise from the characteristics of the CA glue itself, and its tendency to grab the panel pretty much instantly as it touches the frame, the next challenge I found only effects the glue-up of the second bottom panel. Actually this challenge also made properly shaping and fitting the second panel much more difficult than fitting the first panel. This challenge unique to the second panel has to do with clamping.


As I’ve mentioned, the shape of the panel effectively changes as it is bent to the curving contours of the hull. So, even just to properly fit the panel requires that it be clamped firmly to the hull all around, in order to gauge where it needs shaping. In fact, in the process of fitting one of these two bottom panels, I had to clamp it, remove and shape (cutting and sanding - mostly sanding,) then reclamp to gauge progress, and remove clamps again to shape some more, numerous times before achieving the proper fit. While this process was definitely tedious, I saw no other way to accomplish it. This brings us to the challenges unique to the second panel.


The exact shape of the panel can only be determined by clamping down (or otherwise holding it down) to the frame ALL AROUND. The problem is that with the second panel it is impossible to clamp it down on the keel side (or centerline side) because the already glued first bottom panel is in the way. (I considered waiting to glue the first panel until after I’d fitted the second one, but decided it would be impossible to achieve a good fit of the two bottom panels where they meet along the keel/centerline if the first panel wasn’t already glued. Also, even then, I’d have still been unable to avoid the problem when it was time to glue the second panel.)


You may notice, in the two pictures, that I have two screws with washers sticking out of the centerboard well. This was the only way I could think of to apply any kind of clamping to the keel side of the second bottom panel. Unfortunately, the only screws I can find that are long enough, are too large a diameter. I had to force them through the center board well, and now they won’t allow me to get the second bottom panel pushed all the way over, against the edge of the first panel. And even at that, the glue-up of the second panel needs more clamps along that side. The panel fights hard to spring away from the frame, and I don’t think trying to hold portions of it down with my fingers until the glue sets enough to hold it in place against its wish to spring away from the frame, into its natural flat shape, is a practical option.


Alright, I’ve done my best to present my two problems (the challenges of the CA glue, in an application where instantly laying the part in the exact correct position is virtually impossible, and the issue of proper clamping of the second panel.) I hope some of you will be patient enough to read my lengthy explanation. As with the model, I couldn’t figure out a better way!🙂

[derekwarner]

Never a real fan of cyanoacrylate adhesive, however found have that Sika F-40 to be a medium Grade [or viscosity] sufficient to allow a little alignment time prior to the set, or over and above that instant snap set  of superglue Grades with water-like viscosity

The set time naturally also depends on the materials being glued. Applying the superglue to both surfaces can also extend the superglue set time

From the images shown, an alternate approach would be to use a white glue [Titebond III] which would allow any alignment time prior to the clamping you show. then the overnight cure time. This Titebond III provides a near 100% waterproof bond

Derek   

[Circlip]

For some, the setting time of old school glues exceeds their interest span.


 Regards  Ian.

[Geoff]

I usually use Resin W from Evostick (Blue bottle) as this has some grab but plenty of positioning time and once dry is both waterproof and stronger than the wood itself. I am also not too keep on superglue on porous (wood) structural joints as in my experience it can be a little brittle. With Resin W once dry turn the model over and run a fillet of glue along any joint lines. It doesn't shrink when it dries.


Keep up the great work - first build we all learn so much.


Cheers


Geoff

[StrayGull]

Thank you, Derek. I’ll look into the Sika F-40, as an alternative to the CA glue I have now. And I’ll also check out the Titebond III. I used Titebond on the frame, but it wasn’t type III. I guess Sika seems like it’s probably a better alternative, since it’s good enough for the minions!

[StrayGull]

Wise words, Ian, I’m sure! 

[StrayGull]

Thanks, Geoff! I will check out the Evostick you mention. I like the words “plenty of positioning time.” If this glue is “gap filling,” it might prove a good alternative. And since you mention that it doesn’t shrink, I’m betting I’d it is!