Scutum reconstruction - advice needed

[Tarbicus]

Well, it's taken forever to find a decent source of parchment rawhide within the UK for my scutum (note: suppliers in the USA refuse to export a single piece - too much hassle).

Now the hide glue is the problem, but there is a source in the USA and I'm sure that won't be a problem at Customs.

My question is, do you think I should use hide glue, or bone glue? Hide glue seems to be the strongest, and is compatible with sinew. Just thought I'd ask for opinions before it gets very messy in the Tarbicus household.

As a recap, this is what I intend to do:

Bare scutum with metal fittings already made by Len Morgan ("Augustan" shape, plywood).
Layer 1 - Linen soaked in hide(?) glue with sinew fibres mixed in.
Layer 2 - Parchment rawhide (ala Dan Peterson).
Layer 3 - Encaustic paint (plain red, no painted decorative motifs).
Layer 4 - Metal furnishings for the decoration and further reinforcement.

Based on advice given of the Dura scuta (thanks Antonius Lucretius and Drsrob), and many finds of metal furnishings thought to be for scuta.

The plan? Throw heavy pila at it to see if they bounce.
If they don't? Kick a dog and weep like a small child.

[Arthes]

Kick a dog and weep like a small child.

You mean man lol:

[Tarbicus]

Kick a dog and weep like a small child.

You mean man lol:

As if I would................. weep like a child, that is :wink:

[Peroni]

Salve,

A friend of mine recently made a reconstruction of a leather covered scutum with applied metal fittings.

Picture can be seen here http://i20.photobucket.com/albums/b242/ ... metal1.jpg

regards,

[Tarbicus]

Thanks Peroni, looks very nice indeed. I was just reading the pages by Travis Lee Clark posted on the musculata thread ([url:dphlzma9]http://astro.temple.edu/~tlclark/lorica/bronze_leather.htm[/url]). Interestingly he believes that the materials would have been painted over for a more glamorous (and intimidating) effect. Just wondering how an embossed and painted Medusa's head would look on the umbo.

Since nearly all ancient statuary was painted, it appears that the same held true for the musculata as well. It seems odd that you would make this fabulous object out of bronze only to paint it, but that seems to be the practice.

[Matt Lukes]

Hi Jim,

I just happen to be working on a 100% authentic scutum right now (made of 1/8" strips of birch and everything) and I've been using hide glue for everything- so I did a good bit of research on how to use it. It is supposed to be a lot stronger than bone glue, so it is the way to go. You'll need a fair bit to glue on the fabric and rawhide, so I'd order at least 500g of dry glue. It comes in various strengths described in grams (192g, 315g and so on), and as the number increases, so does the strength, and the working time decreases. I used a mixture of 192g and 315g. My source is [url:2cqvavgi]http://www.violins.on.ca/[/url]. The site has a pretty good explanation of how to use the glue too.

Matt

[Tarbicus]

Thanks Matt, that's what I needed to know. Very much appreciated!

Are you gonna throw sharp pointy things at yours too?

[Matt Lukes]

No problem Jim- happy to help.

Throw pointy things at it? OH NO- it's for a client, so no pointy thing throwing :lol: Anyway, it's taken a LOT of work to make so even if it were mine, I don't think I'd risk damaging it. Besides, I really doubt it'd stand up to a pilum- especially a weighted one. They've effectively got armor-piercing points afterall and that's a fair amount of mass behind the point. I doubt very much that even layers of rawhide, glue with sinew in it, linen, and wood will keep it from at least punching part way through. An arrow, sure- a sword, axe or spear, sure- but a pilum? Hmmmm...

I've worked-out a somewhat easier way to mix the glue too:

in a regular teacup or mug mix a roughly 2 or 2.5:1 ratio of cool water and glue crystals. Add the glue to the water slowly to help avoid clumping, then mix with a stir stick. Let it sit until the crystals absorb all the water (maybe 15 minutes)- until when you try to mix it it's all little gelatin blobs. Warm some water in a pan on the stove at very low heat- if you have a thermometer, make it around 70C. If you don't, then just keep it a bit warmer than the hottest water you can get from your tap (most water heaters go up to about 60C I think). Twist up some aluminum foil and make a ring that will hold the cup off the bottom of the pan (the water should heat it, not the pan). There should be enough water to immerse the cup about half way. When the water's up to temperature, put the cup in and let the glue liquify. Stir it periodically until all the particles are melted. Don't worry if a skin develops on top, just mix it back in. Once everything's melted, the glue is ready to use. Just brush it on. Do make sure not to overheat the glue- it's protein, so excessive heat will break it down and weaken it.

Hide glue sets by cooling, and it gels pretty quickly so I've found it best to work on a smallish area at a time. If it gels before you put together whatever you want to glue, it won't work very well. With fabric, for example, I brushed glue on an area about 15x30cm then pressed the fabric down, waited a bit for it to set, then proceeded to the next area. When it's just gelled, there isn't much adhesion, so you do have to be careful not to pull apart what you've just glued. I generally worked from the middle outwards- gluing an area on one side of center, then the other, back and forth allowing each side to set a bit while I worked on the other. You shouldn't try to reposition anything once the glue starts to gel either, so it's important to do any adjustments as soon as possible. Then just let everything dry overnight.

Do remember that hide glue is not waterproof and will soften if it gets wet, so you must wax everything to keep any moisture out.

Matt

[Matt Lukes]

Oh, and one more thing: I do wonder about taking the whole 'linen soaked in hide glue' idea literally- that would be REALLY REALLY messy, and not very easy to do given all the difficulties in working with hide glue- consistent, low heat, fast gelling time, etc. My purely practical impression is that it would be linen glued to shield and then brushed with more glue to saturate it.

And the idea of bits of sinew mixed in seems a tad 'iffy' too unless you're really careful to separate all the fibers and cut them to rather small lengths- if you didn't, I'd expect some rather significant clumping and since hide glue dries rock hard, would leave you with a sandpaper finish or worse. It seems more likely to me that short fibers would be maybe sprinkled over a wet or just slightly gelled surface, smoothed out with fingers and another coat painted on after its dry.

I do wonder about the inclusion of sinew at all though- unless it's in a solid mat of fibers several centimeters long, I don't really see what benefit it would be. I've heard the idea that it was a form of ancient 'fiberglass', but then that's what the linen saturated with glue is, yes? And there's still a layer of leather or rawhide on top of that, so would little bits of sinew do much of anything?

What's the evidence for sinew in the glue in which the linen is 'soaked' anyway? For that matter, what's the evidence of parchment rawhide and not leather as the outer face of a scutum?

Matt

[Tarbicus]

Fantastic - thanks Matt, you're an absolute star!

Are you mixing sinew fibres in with the glue? The reason I ask is that the Simon James report says the linen was *soaked* in the glue and sinew. I was thinking of making a large batch of glue in a glue pot, then once it got to the right temperature and consistency mixing in the sinew fibres and giving it a good stir to make sure they are distributed well. Then, literally dunking and soaking the linen until it was completely soaked through with glue and fibres, pull it out and apply the whole sheet to the wood making sure it was completely pressed down.

Maybe I'm taking it too literally, but that would ensure there are sinew fibres on the outer face of the linen as well. I was also going to use a linen sheet that is oversized and trim the edges and umbo hole once dry.

Here's the tricky bit - while the glue is still wet I would then quickly apply the pre-prepared rawhide. hock:

Sounds like a recipe for disaster I know, but provided everything was prepped right, including in my head and I don't flinch, it should work (best laid plans...).

It's the sinew fibres that fascinate me, and I want to make sure they are on both sides of the linen. I'm also worried that using a brush will make them bunch up and become uneven.

I really doubt it'd stand up to a pilum- especially a weighted one.

Well, cricket bats and mallets use rawhide. I remember some of the guys on RAG testing artillery bolts on a seg and they didn't penetrate. Fingers crossed the multiple layers on the scutum will be just as effective, and a little battle damage should give the scutum a bit of character :?

addendum:
Matt, here are the links I also found on working with hide glue:

[url:3go9uspb]http://www.frets.com/FRETSPages/Luthier/Data/Materials/hideglue.html[/url]
[url:3go9uspb]http://www.nativewayonline.com/glueinst.htm[/url]
[url:3go9uspb]http://www.woodweb.com/knowledge_base/Hide_glue.html[/url]

Not as good as the link on the violin webpage, but my last link has a nice tip:

A small twig of fresh willow with the outer bark removed will prevent mold growth, as will an aspirin, in the glue.

[Matt Lukes]

Thankyou, thankyou- no autographs please

Seriously though, my first question is how could James know that the linen was soaked in glue as opposed to what I suggested? I doubt very much that there would be any definitive way to distinguish one from the other. In both cases the fabric is saturated, so should appear essentially the same. I wonder if its simply a postulation on his part and having never worked with hide glue himself, he doesn't realize that the idea isn't particularly practical. He might also have meant that the fabrick was saturated and just chose the word soaked to indicate that as opposed to intending to suggest an actual method of manufacture.

Does he happen to mention how much sinew is in the glue, its density on the linen or even how he knows it's sinew and not just hide source contaminant in the glue (hide fibers getting in when the glue is being made)? Saying its sinew should mean he proved thats what it was, but one has to bear in mind that hide is fiberous too, and hide glue comes from hides...

As for making a large batch of glue and dunking the fabric, well as I said, I think that would be a REALLY messy affair and might turn out to be very difficult. Hide glue is very sticky on the hands and where it's liquid at 70C, it gels at around 40C, which it reaches fairly quickly once its out of the pot and in the air. You'd need to wear something disposable, gloves and either sock you don't like or some kind of foot covering, set up a big tarp to catch the dripping glue, you certainly wouldn't want to take long letting the excess glue drip off, and you'd have to position the scutum in such a way as to be able to lay the fabric on straight on the first go- before the glue gels. That's fine for the front, since that has a smooth surface, but the back with the stiffeners?

If you still want to try it, I'd think you'll need more than the 500g of glue I mentioned- I used that much brushing- and I'd thin it out a little more than 2.5:1 too. A good 'pot' for doing the dunking would probably be one of those long narrow wallpaper soaking trays- if you can suspend that in some hot water, you can prepare the glue on the stove, then pour it into the wallpaper tray and it should stay liquid while you use it. You don't want the glue to start gelling in the tray afterall.

You wouldn't actually necessarily need to add the rawhide while the glue on the facing linen is still wet- hide glue sticks to itself as well as to anything else so you can just brush on another coat later and glue on the rawhide. Now usually, rawhide is used wet so one can form it, but when I was experimenting with the glue, I found that trying to glue lightly dampened pieces of wood didn't work at all. I'd certainly recommend that you test the glue on a small piece of rawhide to determine how it works before you go for the full-size piece. You may have to form it on the scutum wet first, let it dry and glue it on then. Given that's what it's made from, as I understand it hide glue LOVES rawhide, so it should glue up nicely.

The sinew fibers are interesting, I agree, but if I could be sure that James accurately identified them as sinew and just how much was there, I'd be able to wrap my mind around the purpose a little better. As I wrote before, unless it's an even layer of longish fibers, I just don't see the point. A small amount of sinew fibers isn't going to do much...

You're right that the issue of them clumping would be major if you brush on the glue and this might lessen a fair bit with the dunking method- although you'd have to be careful not to introduce clumps when you smooth the linen out.

Battle damage would definitely give your suctum more character

I'm really curious to hear how it all works our for you!

Matt

[Matt Lukes]

Oh, and while the suggestions of anti-mold measures are quaint, I believe they're for a case where you intend to store prepared glue for more than a day or two in the fridge- which isn't a great idea anyway since hide glue will putrify. Everything I've read suggests it's best to only mix up what you'll use and make it fresh each time. I've stored small amounts in the fridge overnight and it works just fine when re-heated. Adding anything- especially crushed aspirin sounds to me like a good way to weaken the glue...

Matt

[Valerius Valentinus]

A note on hide glue - I am surprised how strong hide glue can be. Some of the plank shields I have made have stood up to time. If a glue bond brakes it reseals itself over time due to damp weather followed by a dry spell.

En caustic paint - I do not know if you are to use modern forms of this paint so I can not comment but if you intending to make your own en caustic paint using beeswax then some advice - Do not paint on top of paint, it builds up and is easily knocked off. If you changed your mind and decide to paint a motive do the motive first then paint red around it. The finished product should not be smooth. You should be able to feel all the short brush stokes as well as see them.

Paul Carrick

Valerius Valentinus COH V GALLO

[Tarbicus]

Seriously though, my first question is how could James know that the linen was soaked in glue as opposed to what I suggested? I doubt very much that there would be any definitive way to distinguish one from the other.

I'm being literal, and I'll carry on that way shock: KICK THE DOG!!

[Matt Lukes]

Me too hock: KICK THE DOG!!

Just give him the scutum first More battle damage!