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So I see a lot of you referencing use of CA accelerator however I so often generate a lot of white stuff as a result. I don't have to tell you what a bugger it is when it gets into the cavernous pores in Wenge for example.
Couple of questions:
1. What causes that?
2. What techniques do you use to minimize this?

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Doug

Don't let fear or common sense stop you from trying to build something

I found the key to this problem a little while ago and have been meaning to post it here on the forum. There is a new accelerator on the market called Gluboost. It is a CA accelerator that was designed with instrument building and repair in mind. I've been testing it for a couple months and it works as the maker describe. The glue dries quick, but without discolouring the glue. It is also safe on instrument finishes (I think they say most finishes). I am now using the stuff all the time. I wish they offered it in a liquid form, but the aerosol can works well for most applications. It is well worth the cost and they do ship to Canada.

http://www.gluboost.com

Josh

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Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
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House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

A finer mist of accelerant and/or thinner layers of CA... it seems a big drop of accelerant on a big blob of CA is a recipe for frothing.

The technique I use is a simple one... I don't use the stuff

CA is fast enough aint it?

I use star bond CA and accelerator. Works fine but you need to wait about 15 seconds before you spray. Also less is better. It doesn't take much.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I just ran into a problem with standard accelerator last night on a repair job. Not a big deal but annoying. I checked out their site and accidentally ordered a can - - too easy with PayPal

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Steve Smith
"Music is what feelings sound like"

Exactly. Should last a long time if only used on those special cases.

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Steve Smith
"Music is what feelings sound like"

How do the fumes of GluBoost compare to the usual accelerators?

This is all good info and I am thankful. I would, however, like to get back to the spirit of the original questions. Am I applying too much CA? Too much accelerator? Wait time in-between? Should one spray directly or indirectly? What is the cause of the whitening? How does one minimize this effect?

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Doug

Don't let fear or common sense stop you from trying to build something

The cause of the whitening is when CA cures, it generates heat. When accelerated, it generates enough heat to cause the glue to "boil" as it cures. The whitening is entrained bubbles.
So, less CA, less accelerator, more time before the accelerator, or some combination.

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

In American Lutherie #113, the article by Andrew Morry on binding F5 mandolins :
'Ebony can be somewhat acidic, and superglue needs to be slightly alkaline to cure properly, so I brush all the gluing surface of the ebony with a bit of baking soda dissolved in water and let it dry for a little while before installing the binding. The baking soda and any residual moisture act as a mild accelerator, making the superglue cure quite quickly. However, the glue doesn't turn white, as it can with some commercial accelerators.'

I haven't had the occasion to test this myself to see how well it works, but I thought it was worth mentionning and made for an interesting bit of information.

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Not much but at least it exists : http://jbluthier.com/

Baking soda is a known accelerator. You can even dust the surface with it and dust off the excess then install the binding/purfling and wick in the CA. The residue will accelerate the drying without the white stuff.

To give proper credit, I believe I learned this from one of Grumpy's posts (First Epoch Grumpy).

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

What he said. If I need CA to stay clear, I apply it drop by drop in stages and just go away for awhile between. Moderating the amount of accelerator is a better solution if you don't need 100% certainty, and a big blob of CA will still probably generate enough heat to boil up even without accelerator once it kicks.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

I learned that from a "Model Airplane News" hints and kints section back in the 70's I think!

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http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

...has test drilling revealed the promise of any shale-cyanoacryllate to be found in the stratum between 1st and 2nd Grumpy Epochs...? if so I have several patents on acetone-based hydraulic fracturing(employing "proprietary" detergents); if so we could be in CA for approximately 1.76 generations

Great input everyone. Thanks!

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Doug

Don't let fear or common sense stop you from trying to build something

Odorless CA does not turn white. It's more expensive, but IMHO worth it.

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John

What is the brand name?

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Doug

Don't let fear or common sense stop you from trying to build something

Bob Smith Industries (BSI)
Thin odorless = 'Super Gold'
Thick odorless = 'Super Gold +'
Bob Smith also makes regular CA in several viscosities, and I think it is the best (no affiliation). It is generally seen in hobby shops. I mail order it from these guys:
http://www.gravesrc.com/BSI_THIN_FOAM_SAFE_CA_2_OZ_p/bsi123.htm

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John

I accept the price, because I am extremely allergic to regular CA fumes. The 'non foaming' trait has been an extra bonus, particularly when doing finish touchups.
As you can see in this link, the BSI 'standard' CA is priced more in line with other brands. Remember, this is a 2 ounce bottle, which lasts a very long time, even for someone who uses it almost daily.
http://www.gravesrc.com/BSI_THIN_INSTA_CURE_CA_2_OZ_p/bsi103.htm

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John

Moderating the amount of accelerator to eliminate the whitening is correct. IMO the best way to do this, as it is very difficult to spray a desired amount, is to spray and wait a minute or two before sticking pieces together. The accelerator has a half life and loses its intensity over a short period of time. I never get whitening doing it this way. This method lends much more control than trying to spray a certain amount of the stuff.
I love using accelerator with CA. It allows me to keep a flow going in the shop that I wouldn't have if I had to stop and hold pieces together for 30 seconds. Call me impatient but it's a dance that happens and stopping a movement stops the dance for me.

In all cases where I have encountered white CA it has been due to crazing. Internal stresses from the curing process generate microscopic cracks, and a lot of them. Slower curing formulas would help, but they are heavily filled with fumed silica, which can easily prevent a crystal clear appearance on its own. If you insist on using accelerant do not apply it to the adhesive. Apply it to the substrate (fully cured CA is okay in this case.) All the reaction needs is a basic pH at the interface. Ammonia works well, and all of the accelerator sprays contain electron donors in solvent (typically heptane.) If you take your time and allow the CA to cure naturally you will achieve the best possible result, which is as clear as acrylic.

I've never conducted experiments to validate my next idea, but I expect it would work well. Place the CA in a refrigerator overnight before use. Apply normally and allow at least 24 hours to cure. This should slow the reaction rate dramatically and allow a highly disorganized clear polymer matrix to form. I might give this a shot sometime this week. Otherwise if anyone feels like wasting the time of some people at titebond I bet they will run a similar test series. If you go that route just make sure to ask for bob and don't tell him I suggested contacting him (he hates me.)

I'll post results if I get around to running the test. BTW, it's okay to add accelerator to the surface with cold CA. The reaction will initiate although it will be very slow. It might not be a bad idea to finish the reaction using a blow dryer. It should drive the reaction towards exhaustion and relieve some internal stresses as it will soften to some extent.

Out of curiosity, would anyone be interested in having a hot glue system that extrudes a thin bead of melted acrylic plastic? It could perform at least as well as other reactive technologies but would be a thermoplastic and have good strength characteristics under a variety of stresses? If so, I have an idea in mind that would make use of existing products. Yes, this could make use of different colors as well and would be suitable for being tooled and polished after setting. So you could make exotic cast inlays... If this hasn't been patented yet I'm claiming it!

We have been involved with CA glues and accelerators for many years and have tested many types. We have found that MasterGlu Thin all purpose CA will not foam when used with GluBoost accelerator. Also, MasterCoat for dings and dents as well as instrument finishing, will also not foam or white with Gluboost accelerator. Additionally neither of these products will yellow. You can find them here. www.gluboost.com. Thanks.

Rick Rosenberg
President
Gear Up Products, LLC
www.gluboost.com

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Rick Rosenberg
President
[url]www.GearUpProducts.com[/url]
[url]www.ricksguitartalk.blogspot.com[/b][/url]
[url]www.gearupproducts.blogspot.com[/b][/url]