smooth - on

[purple heart]

New to smooth on.  Probably a dumb question, but, why does it bubble up so bad while mixing and what do you do about it?  I mixed it slow and it was just a froth when I felt it was completely mixed.  Never did settle so I went ahead and used it anyway.  Was afraid I was running out of working time.


   Also,  does it need the heat from a hot box to get a stronger cure or do you guys just do that because you don't want to wait the 16-20 or so hours for it to cure at ambient temp's.

   Basic questions here, but, I sure would be interested in your feedback......Thanks

[kennym]

It's just thick enough to trap some air while stirring.

I've done both ways,waiting and just going ahead,no probs either way. I use a wooden paddle to lay it on the lams,all bubbles are gone when the glue is spread.

Most bowyers use heat because when the glue reaches the cure temp in a strung bow(like seat of closed vehicle ) it may delaminate.

[purple heart]

Thanks Kenny --

I wonder if I got a bad batch or something....This stuff was so thick I had to literally spoon it out of the can (seemed almost dried out).  The bubbles never settled even as I spread it as thin as I could with a tounge depressor.  Anyway, took it out of the heat after 8 hours and it is misty with micro-bubbles.  Any further thoughts?  It just didn't seem right from the start.  

Thanks again, Kye.

[sw]

Hi there kye,

We use Smooth-On on about every bow built. It is THICK! especially the part A, part be is like thick honey, but Part A (white) is paste.

We get bubbles every once in awhile when mixing it - its no issue, as said above use a paddle or flat blade to spread it onto the work surface, i have never seen a air bubble after its been cured. We cure ours at 150 to 185 degrees for 4 to 6 hours, Kenny points out it will delam when it reaches its cure temp so it is best to use heat and an air system to lam it with - heat and pressure = GOOD.... We use 45 to 55psi air hose depending and never have had a delam.. yet... *knock on wood*

Hope that helps, oh and i like to use the by weight measurements 100/83, again never have had an issue BUT rom what i have heard the glue has a pretty forgiving window in mixing too - never pushed it tho....

Dave

[Tom Leemans]

I watched Byron Fergusun use a fingernail brush to apply it. He claimed it applied just the right glue film.

[purple heart]

Thanks for the feedback fellas ----


Kye

[Apex Predator]

What temp are you mixing it at?  During the winter I have to pre-warm it, or it's really thick and hard to handle.

[Robertfishes]

I just glued up my 4th bow using smooth on. I had no previous lamination experiance before these bows.  I bought a couple of 1 1\\4 inch wide paint scrapers and some plastic squeegees used for Bondo and cut them to 1 3\\4 inchs wide. For me the plastic bondo applicators work the best. The first couple of passs over the lam I put some pressure on the applicator pushing the smooth on into the lams filling any voids in them, then lightly go over them to make sure there are no dry spots. Right or Wrong this is how I have done it, so far no problems. I have been curing the bows at 160 -165 degrees for 5 hours. I have a lot to learn and have bled on all 4 bows so far..thinking about making some broadheads out of smooth on.

[purple heart]

Apex --  It was about 75.F in my shop when I was mixing the glue.  That thought crossed my mind as well, but I figured that was warm enough.

Thanks for the feedback --  I will press on!

[Mike Mecredy]

I never heard of it becoming a "froth"  Never seen it either.  I use it a lot.  I've used 2 gallons so far since February and just got my 3rd gallon in the mail.  it's lots easier to mix at about 75 F. and over.

[C. H. Hayden]

I'm trying to get the formula right for making wood/carbon recurves. Have tried System Three and 3M since I sell them and get samples, but the stuff must have too much flex; after curing and post curing the bow limbs work fine but when you unstring the bow the limbs don't fully recover to shape. Anyone have this problem with Smooth-On? I've ordered some to try, hopefully the harder epoxy will work better. Interesting thread above, Robertfishes says he cuts himself on the epoxy residue. Never have had that problem with the epoxies I've used, but they are for building boats mostly. They are so flexible when cured any thin stuff left over can be rolled up.

[Robertfishes]

C.H. I cut myself because I did not put on leather gloves during edge sanding the hardened squeezed out glue on the bow sides, Totaly my fault and it will not happen again.. I would say the glue/epoxy you are using is not suitable for bow building but you already know that. I think Smooth on is what most people use, I have a friend who works for a bow manufacture uses something called Vesamid? good luck with your next build.

[Tom Leemans]

Heating it in the box probably gets rid of most, if not all of any bubbles left over. I know when you use that epoxy bar coating stuff, you get rid of the bubbles by running a hair dryer or heat gun over it for a few seconds. The bubbles disappear right away.

[droptine59]

I raise the room temp in my shop to about 80. it seems to loosen part A and the mix is "slightly" more viscous but still THICK. I use a printers ink spatula to mix and it seems to keep bubbles from forming.