First dip troubleshoot
Moderator: Titelines
- fragmentum
- Master Guide
- Posts: 598
- Joined: 02/21/15 11:50
- Location: Missoula, MT
- Contact:
First dip troubleshoot
#1I just completed my rod dipping setup. The dip tube extends down into my crawl space from within my drying cabinet and is a heated PVC 5 foot tube with a 'draw cup' at the top.
My pull rate on this first test tip section was 3 inches/minuet. I heated Helmsman Spar Urethane to 100°-105° and heated drying cabinet to 90°.
I started pull, ferrule end up, without hesitating. After tip was 2/3rd pulled I noticed runs forming 6-8 inches below the top so stopped the pull and took the section out of the cabinet and wiped it down. I started the process from the beginning again. This time I stopped to allow more drain time by using 10 seconds pull/10 seconds hold through the entire pull. No runs and section shows no start/stop marks in the finish.
Questions I am pondering: Urethane too warm? Cabinet too warm? Both? Pull rate too fast? Combinations of any/all three???
I know I need to do some more experimenting with all the variables at play here. The start/stop intervals could be extended safely, I believe, depending whether it is a butt or tip section. I don't really want to deal with dried runs in the first dip regardless if it is the first dip or not. I only want to buff between coats, not 'fix' between coats...
Suggestions?
Thanks!
My pull rate on this first test tip section was 3 inches/minuet. I heated Helmsman Spar Urethane to 100°-105° and heated drying cabinet to 90°.
I started pull, ferrule end up, without hesitating. After tip was 2/3rd pulled I noticed runs forming 6-8 inches below the top so stopped the pull and took the section out of the cabinet and wiped it down. I started the process from the beginning again. This time I stopped to allow more drain time by using 10 seconds pull/10 seconds hold through the entire pull. No runs and section shows no start/stop marks in the finish.
Questions I am pondering: Urethane too warm? Cabinet too warm? Both? Pull rate too fast? Combinations of any/all three???
I know I need to do some more experimenting with all the variables at play here. The start/stop intervals could be extended safely, I believe, depending whether it is a butt or tip section. I don't really want to deal with dried runs in the first dip regardless if it is the first dip or not. I only want to buff between coats, not 'fix' between coats...
Suggestions?
Thanks!
Re: First dip troubleshoot
#2Raising the temperature of the poly will lower the viscosity. The withdrawal rate must be matched to the viscosity. If you cannot adjust the withdrawal rate, then you will have to reduce the viscosity by cooling the poly. You could try to adjust your withdrawal by removing the wood spool and just winding on the motor shaft.
Galt
Galt
- dbeerbower
- Guide
- Posts: 142
- Joined: 02/01/14 10:14
- Location: Wildwood,MO.
Re: First dip troubleshoot
#3First off, you have a first class dip set-up. Nice job. I think the temperature is fine. My guess is that you need to slow down the withdrawal rate to about 2 feet per minute. I stop at the top of each wrap and the bottom of each wrap for 60 seconds apiece. The snake guides clear themselves nicely at that speed but you may need to break the surface tension bubble at the stripping guide as you pull out of the varnish. This should stop any further issues with runs. If the varnish is old, you may need to add some thinner if the problems continue.
- Dave Dozer
- Guide
- Posts: 190
- Joined: 07/12/11 18:00
- Location: Sisters, Oregon
- Contact:
Re: First dip troubleshoot
#4Yep, what dbeerbower says is most likely right on. Runs in varnish often come from the bubble that forms in one of the guides. I pop/wick the bubble that forms on any of the guides with a pointed piece of paper (I use heavy water color paper), but you can probably use just about anything...a toothpick might work well. Here is a photo of how I take care of these "guide bubbles.
Dave
Dave
Re: First dip troubleshoot
#5What dbeerbower and Dave said. (although I think dbeer meant two inches per minute). I draw at 1.25 inches per minute with unthinned Helmsman and aside from the stripper I do not stop; at the stripper I use the paper thing or a toothpick or whatever I can grab at that moment. I have watched at the guides but at that slow rate there is never a bubble on the guide with which to deal. No drips, no runs (like the Yankees) no errors.
Re: First dip troubleshoot
#6I don't dip with guides on so I will leave that to others, I always orient the strip with the small end "up". If you do it the other way you have "more" varnish running onto a smaller surface area which causes problems as the varnish has nowhere to go! You don't get these problems the other way around, just food for thought.
- fragmentum
- Master Guide
- Posts: 598
- Joined: 02/21/15 11:50
- Location: Missoula, MT
- Contact:
Re: First dip troubleshoot
#7Galt, I timed the shaft only pull at 1 inch/minuet. The spool has an indentation in the middle, probably turned on a lathe by the previous owner. I timed this pull with that groove at 2 inches/minuet, so when I eliminated the grove to speed up the pull it went to 3 inches/minuet.galt wrote:Raising the temperature of the poly will lower the viscosity. The withdrawal rate must be matched to the viscosity. If you cannot adjust the withdrawal rate, then you will have to reduce the viscosity by cooling the poly. You could try to adjust your withdrawal by removing the wood spool and just winding on the motor shaft.
Galt
I figured raising the temperature of the urethane that would lower the viscosity and allow, correspondingly, increasing the rate of the pull, but was not trying to balance viscosity-to-pull-rate.
The next test will probably using the grove in the spool and drop the pull rate to 2 inches/minuet and leave all other variable alone. We'll see how that thin urethane drains off.
dbeerbower "2 feet per minuet"???? Thanks for the compliment...dbeerbower wrote:First off, you have a first class dip set-up. Nice job. I think the temperature is fine. My guess is that you need to slow down the withdrawal rate to about 2 feet per minute. I stop at the top of each wrap and the bottom of each wrap for 60 seconds apiece. The snake guides clear themselves nicely at that speed but you may need to break the surface tension bubble at the stripping guide as you pull out of the varnish. This should stop any further issues with runs. If the varnish is old, you may need to add some thinner if the problems continue.
dbeerbower and Dave Dozer; I guess I should have mentioned in the initial post... I am not dipping with guides, just the section with the ferrule attached. I probably won't be dipping with guides on new rods, only on restorations if necessary.
Re: First dip troubleshoot
#8reduce pull speed-1 to 1 1/2 "/minute would be better, don't heat the varnish, and as long as your drying area is above 70* don't heat it any further. Stopping at the bottom of each guide is a good idea. If viscosity is correct the varnish should self clear at guides.
Re: First dip troubleshoot
#9Jimmy is right about tip up; it works to keep the corners a little "crisper". Also, I dip twice without guides and then once more after the guides are attached. The
- fragmentum
- Master Guide
- Posts: 598
- Joined: 02/21/15 11:50
- Location: Missoula, MT
- Contact:
Re: First dip troubleshoot
#10- dbeerbower
- Guide
- Posts: 142
- Joined: 02/01/14 10:14
- Location: Wildwood,MO.
Re: First dip troubleshoot
#11Yes, I got too excited. 2 inches per minute is correct. Glad the last dip went well
- fragmentum
- Master Guide
- Posts: 598
- Joined: 02/21/15 11:50
- Location: Missoula, MT
- Contact:
Re: First dip troubleshoot
#12Thanks! Yes, I am stoked that the tool I built is giving me the results and quality I expected. May be some fine tuning here and there, but 'out of the box' it works!dbeerbower wrote:Yes, I got too excited. 2 inches per minute is correct. Glad the last dip went well
- fragmentum
- Master Guide
- Posts: 598
- Joined: 02/21/15 11:50
- Location: Missoula, MT
- Contact:
Re: First dip troubleshoot
#13Had to widen the 'V' notch in the spool on the pull motor because as the string was being wound on the spool, it was also climbing up one side of the 'V' and this was also increasing the pull speed. I want the pull speed to be the same throughout the entire pull.
Inspecting the last dipped hex sections, the apexes are staying nice and defined/sharp. Usually one type of varnish/urethane or another will have a tendency to 'pool up' or load up on the apex or the flat of whatever it is that you are dipping. I think the heating up of the varnish/urethane or whatever liquid 'sauce' your using applies so much thinner and allows you to steel wool and/or sand smoother between coats, and keeps the coats down to a more manageable thickness.
Inspecting the last dipped hex sections, the apexes are staying nice and defined/sharp. Usually one type of varnish/urethane or another will have a tendency to 'pool up' or load up on the apex or the flat of whatever it is that you are dipping. I think the heating up of the varnish/urethane or whatever liquid 'sauce' your using applies so much thinner and allows you to steel wool and/or sand smoother between coats, and keeps the coats down to a more manageable thickness.