Accelerating Oil-based Poly Cure Time

[crokett™]

I'm applying finish to a ukulele that I'm building.  12 hours after applying a wipe on coat, it's still a little tacky.  It's Watco wipe on oil based poly.  I'm working in the house because my shop is not heated and it is very humid here (rain).  Is there a way to speed up the cure time?  I'd really like to move on to setup so I can play it 

[fredhargis]

A fan blowing across it will accelerate the curing, but that has it's downsides (dust nibs).

[Admiral]

I'd wait it out on the first coat, but I've always found the oil based "wipe on" formulations a bit thick for my taste. For the last decade or more I've been rolling my own wipe on finish, cutting oil poly 50-50 with MS; dries much faster but down side is you have to put on 4-5 coats to get your desired (at least my desired) finish. If you are putting on another coat, think about thinning it a little bit with MS.

[crokett™]

Thanks Fred. I was wondering about something like a low temp oven. I could put a filter in front of the fan

[jteneyck]

What Fred said; air flowing over it will speed up the drying.  You could also add a few drops of Japan drier to the subsequent coats, but from my experience it's the first coat that takes the longest to dry because of how much gets sucked into the wood.  Once the surface is sealed the subsequent coats dry more quickly.  

John

[Stwood_]

A fan blowing across it will accelerate the curing, but that has it's downsides (dust nibs).

+1

[crokett™]

I moved it to a room with a ceiling fan running. I think the air movement helped. It is dry to the touch now. I was following the directions in the kit and used a foam brush to apply the poly. I'll wipe on the next coat in a bit and see how that does instead of the brush. I'm hoping I can string it and set it up tomorrow.

[Cooler]

Stu-mac is the premier supplier of supplies to the luthier industry.   They recommend this finish.

https://www.stewmac.com/luthier-tools-an...cquer.html

[crokett™]

Stu-mac is the premier supplier of supplies to the luthier industry.   They recommend this finish.

https://www.stewmac.com/luthier-tools-an...cquer.html

Noted.  their instructions (and videos) for the uke kit build give directions for a Poly finish.  I wondered about lacquer.  My next attempt may use lacquer.  We will see.  I'm not sure what the difference is between guitar lacquer and regular lacquer.

[Cooler]

Noted.  their instructions (and videos) for the uke kit build give directions for a Poly finish.  I wondered about lacquer.  My next attempt may use lacquer.  We will see.  I'm not sure what the difference is between guitar lacquer and regular lacquer.

A discussion on the merits of poly vs. lacquer.

http://www.huffmancustomguitars.com/post...-urethane/

https://www.seymourduncan.com/blog/lates...and-hazard

And this from Fender Guitars:  https://www.fender.com/articles/tech-tal...f-finishes

Fender's current preference is polyester, which I have never heard of for woodworking (it is the finish of choice for powder coating as it is highly UV resistant, but not as scratch resistant as epoxy).

I will have to try this sometime soon.

http://www.milesi.us/en/news/356-milesi-...ng-systems

And ICA lists a polyester finish for luthiers:  https://www.icanorthamerica.com/us/en/po...r_coatings

Available from Grainger:  https://www.grainger.com/product/4CY67?g...3:20500731

And this puts the kabosh on all the above:  http://www.cavalierifinishing.com/polyes...ne-finish/

Polyester is a three-component paint that utilizes the resin + catalyst + accelerant. Thanks to its tight molecular structure, polyester has a solid content of +/- 96% which gives the product superior mechanical and chemical resistance, and limits the VOC content dispersed into the environment. Once catalyzed and dry, polyester emits no further VOC’s into the environment making it harmless to interior air quality.

The application of this class of finishes requires specialized equipment and machinery to produce a quality product. Polyester is specified when high scratch resistance and 100% sheen are required on commercial and residential projects, and when LEED compliance is necessary.