CA glue and cracks

foxtrapper · Post by **foxtrapper** » Wed Apr 04, 2012 1:53 pm

and a clear CA becomes milky and frothy when sprinkled with baking soda.

JPG · Post by **JPG** » Wed Apr 04, 2012 2:19 pm

foxtrapper wrote:and a clear CA becomes milky and frothy when sprinkled with baking soda.

Like peanut brittle?:D

terrydowning · Post by **terrydowning** » Wed Apr 04, 2012 2:25 pm

Yeah, the alkali of the baking soda will react with acid in the CA, generate heat and accelerate curing.

A better filling is sanding dust from the project being worked on. When turning and I have voids to fill, I'll sand enough to bring up some dust, apply some CA and sand some more until the CA gets tacky. this fills voids with sawdust/CA mixture nicely. Once dry, continue turning.

swampgator · Post by **swampgator** » Wed Apr 04, 2012 3:41 pm

Very interesting conversation. From what I am reading, if the cracks are on the end of the board, it's better to discard that portion of the board. If the cracks are internal to the board, and you apply CA, it is better to paint than stain. Sounds as if it is better to use one of the wood glues with some sawdust, especially if staining or applying only varnish finish.
This is really good information. Will do some testing to see what I come up with.

Thank you for all your contributions. Hope this also helps someone else getting a handle on woodworking.

terrydowning · Post by **terrydowning** » Wed Apr 04, 2012 5:07 pm

Actually stain will work fine with CA filling a small crack as long as you scrape off any excess on the surface of the board. Just like you would have to do with any other glue. Larger voids are best filled with wood glue and sawdust or other commercially available products as described previously in this and other threads.

By all means cut off any checking on the end of a board, there's no value in building in deficiencies. Ed's advice in his current nesting box tutorial about cutting around and thereby eliminating deficiencies is by far the best advice IMHO and you don't hear that advice very often anymore.

I was taught to examine and inspect every board purchased or used in a project and I still do much to the consternation of employees at the big box stores (some of them really don't like it when you start going through the stack).

Sometimes when using scrap or cut offs, you have to deal with voids and this thread is a pretty good conversation on what the possibilities are.

I have used the following all with satisfactory results.

commercial wood putties and patch compounds
commercial wood hardeners
wood glue with and without sawdust or chips
white glue with and without sawdust or chips
CA glues with and without sawdust

Satisfactory is of course subjective based on the nature of the project, the level of finish desired and the final finish to be used on a project. If making "Fine Furniture" I would definitely work around any deficiencies in the raw product. For nesting boxes? Jigs? shop shelving and work benches? Fill it in, scrape or sand it smooth and use cheap paint or left over finishing products that always seems to be around.

swampgator · Post by **swampgator** » Thu Apr 05, 2012 12:05 pm

foxtrapper wrote:and a clear CA becomes milky and frothy when sprinkled with baking soda.

Sounds like Gorilla glue. I can't remember the type as my senior moments are occuring.

terrydowning · Post by **terrydowning** » Thu Apr 05, 2012 12:20 pm

CA and Gorilla glue are 2 entirely differnt things.

CA is basically liquid acrylic mixed with a bit of acid to help it bond.

Gorilla glue is a polyurethane based expanding foam. The expanding foam helps provide the bonding here.

swampgator · Post by **swampgator** » Fri Apr 06, 2012 7:47 pm

Thanks, Terry. The only time I used Gorrilla poly glue caused me to toss it. It did foam and I was trying to put back on a piece of veneer. Oops! Won't make that mistake again. It's still there and I did get it finished with an emery board. Thanks for clarifying that.