Not that hard to find - aircraft products...
Randolph Aircraft Products - 210 Dope
https://www.aircraftspruce.com/pages/cs/reducers/dopesthinnrsolvents.php
Randolph Aircraft Products - 210 Dope

https://www.aircraftspruce.com/pages/cs/reducers/dopesthinnrsolvents.php

Epoxies are every bit as dangerous., likely even more so.. but the legislative wizards haven't caught up .. yet.
I charge triple to fix epoxy boards - usually puts the customer off and puts the danger of sensitisation into some one elses workshop.
Only reason why people glass balsa boards with it is because they are too lazy to pre-finish and go poly........
Cellulose dope is the stuff to buy - thin it with slow thinners between 30 / 70 - 50 / 50.
Greebster,
I bet that PT flew smooth as a babies bottom 😀😀😀
No pics unfortunately, they got lost in moving about the country, along with all the rest 🙁
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After all that dope, lets get back on track 😉.
I took the easy way out so far and had a template made with water yet cutting. So no need for the circle template, I can use my router table to cut.
Seemed like the easy way for me to do it.
Also remember if a budget is in mind you can get some rub collars for your router and make your own template out of plywood to clamp on to the baffle instead of buying a circle jig .... just make your template hole bigger to compensate for the rub 1/2 collar and to the whole measurement of bit diameter....
I took the easy way out so far and had a template made with water yet cutting. So no need for the circle template, I can use my router table to cut.
Seemed like the easy way for me to do it.

So is your baffle going to be made of aluminum or wood? I forgot if you said the router was going to be used to cut metal.
Gonna try to cut the aluminium with the router. If that doesn't work out I can always revert to wood. But I have cut aluminium before, just not that much as I have to now.
I changed the original templates with regular HM router bits without problems.
If my 32 year old car didn't require attention I would have cut some already...
I changed the original templates with regular HM router bits without problems.
If my 32 year old car didn't require attention I would have cut some already...
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Could a sealer be "dope" as well?
I'm thinking that we have a lot of different roof sealers, mostly for cement as our roof develop cracks whenever a earthquake hits, so, we must seal the cracks with a coating. It is clear, watered down already and dries as a "clear coat".
I'm thinking that we have a lot of different roof sealers, mostly for cement as our roof develop cracks whenever a earthquake hits, so, we must seal the cracks with a coating. It is clear, watered down already and dries as a "clear coat".
Gonna try to cut the aluminium with the router. If that doesn't work out I can always revert to wood. But I have cut aluminium before, just not that much as I have to now.
I changed the original templates with regular HM router bits without problems.
If my 32 year old car didn't require attention I would have cut some already...
Good luck with the cutting. Take your time, well, you know how to do that by now! 🙂
If it doesn't work out, get in touch with some kitchen renovation contractors. They may have long thin pieces of Corian after doing a project that they would give or sell for really cheap... and it would look amazing.
I cut aluminum on my CNC router all the time. go slowly and don't try to take too deep of a cut and you should be fine. Of course, Carbide is a requirement and some lubricant to keep the aluminum from bonding to the bit helps too.
I did some aluminium cutting this week. It's not exactly going as planned though. I keep trashing the tiny bearings used as a guide/rub collar to follow the template.
Bought a bunch of different bearings to see if that could remedy it but no luck.
The aluminium cutting is going smoothly with WD40 as the lubricant/coolant but the bearings do not survive much more than cutting one hole.
I guess I'm trying to cut to much metal in one go. I pre-cut the holes with a jigsaw but was a bit too conservative. Meaning I cut the holes rather small leaving about 4 mm for the router bit.
(the pre-cut baffle holes done by jigsaw, pain in the ... too with 10mm thick alu)
About 10 holes done so far on the first baffle:
I even tried using a rubber o-ring on the bearing for a more conservative cut as a first go but it cost me the bit, destroying the bearing and giving me a scary moment 😱.
I even tried to use a solid spacer instead of the bearing. It worked but it trashes the template fast. So that doesn't help much.
I'm trying to go as slow as possible, continuously spraying the WD40 but haven't found a recipe yet that works.
Here's some trashed bearings/spacer:
Among the bearings used where high temp bearings, bearings with ceramic balls and plain RC model car bearings.
I can't vary the speed of my router so that doesn't help me either.
But I'll keep trying different things to come up with a workable solution before starting on the baffles that can be seen ;-).
~ to be continued ~
Bought a bunch of different bearings to see if that could remedy it but no luck.
The aluminium cutting is going smoothly with WD40 as the lubricant/coolant but the bearings do not survive much more than cutting one hole.
I guess I'm trying to cut to much metal in one go. I pre-cut the holes with a jigsaw but was a bit too conservative. Meaning I cut the holes rather small leaving about 4 mm for the router bit.

(the pre-cut baffle holes done by jigsaw, pain in the ... too with 10mm thick alu)
About 10 holes done so far on the first baffle:

I even tried using a rubber o-ring on the bearing for a more conservative cut as a first go but it cost me the bit, destroying the bearing and giving me a scary moment 😱.
I even tried to use a solid spacer instead of the bearing. It worked but it trashes the template fast. So that doesn't help much.

I'm trying to go as slow as possible, continuously spraying the WD40 but haven't found a recipe yet that works.
Here's some trashed bearings/spacer:

Among the bearings used where high temp bearings, bearings with ceramic balls and plain RC model car bearings.
I can't vary the speed of my router so that doesn't help me either.
But I'll keep trying different things to come up with a workable solution before starting on the baffles that can be seen ;-).
~ to be continued ~
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Other related news... I bought the expansion card for the Xonar Essence ST giving me some more channels to play with. I am considering using the extra channels for a multi-sub setup (about 3 minimum) and possibly 2 more for ambient channels to play with.
That way I could limit the amount of boost in the lows for the arrays and fill it in with the multi-subs.
That way I could limit the amount of boost in the lows for the arrays and fill it in with the multi-subs.
Are you having someone spray WD40 as you cut continuously? Because it takes this to keep the heat away. If that is not working try a heavier type lubricant spray.... You may also try slowing down your router speed ,high speeds cause excessive heat on the bearings...
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I'm by myself sadly limiting the cuts to less than an inch for a dose of WD40 but it's not nearly enough. As the router is hanging upside down I don't want to flood it.
Can't vary the speed of this router... I bought it to cut wood, never figured I would want to try aluminium. That should have been done using CNC in my original plans (lol).
Can't vary the speed of this router... I bought it to cut wood, never figured I would want to try aluminium. That should have been done using CNC in my original plans (lol).
Have you considered using a guide bushing for the router rather than a bearing? It could mean a different template, but may ultimately be easier to continue working with. Also, I cannot vouch for how well they perform, but there are aftermarket sources for making variable speed router, as here:
Router Speed Control - Rockler Woodworking Tools
I imagine you should be able to source something similar wherever you are.
Router Speed Control - Rockler Woodworking Tools
I imagine you should be able to source something similar wherever you are.
This one's cheaper, maybe available locally.
Router Speed Control
I have zero experience with machine work, but I've always been told wd40 is a solvent not a lubricant. Maybe what's tearing up the bearings is that you're cleaning out the grease? My intuition would be to try a synthetic motor oil, though wikipedia suggests that may pose harm to any brass or copper bits on the router and possibly a smoke/fire issue, esp w/ no speed control).
Router Speed Control
I have zero experience with machine work, but I've always been told wd40 is a solvent not a lubricant. Maybe what's tearing up the bearings is that you're cleaning out the grease? My intuition would be to try a synthetic motor oil, though wikipedia suggests that may pose harm to any brass or copper bits on the router and possibly a smoke/fire issue, esp w/ no speed control).
Thanks guys, I think the variable speed could be the ticket. I've found some options but sadly not at cheap prices yet. I have a 1850 watt router so it must be able to handle that.
I haven't tried cutting dry without WD40 and at my current speed I'm afraid to try.
Previously I did cut parts of my other templates dry but that was 8 mm thick and over very short distances. Due to having the router upside down I wouldn't dare use anything other than WD40 in this case. Other than maybe running dry while moving as slowly as possible. The cutting part works very well, the router bit stays sharp (with the WD40 no clinging aluminium to the bit).
I haven't tried cutting dry without WD40 and at my current speed I'm afraid to try.
Previously I did cut parts of my other templates dry but that was 8 mm thick and over very short distances. Due to having the router upside down I wouldn't dare use anything other than WD40 in this case. Other than maybe running dry while moving as slowly as possible. The cutting part works very well, the router bit stays sharp (with the WD40 no clinging aluminium to the bit).
I have zero experience with machine work, but I've always been told wd40 is a solvent not a lubricant. Maybe what's tearing up the bearings is that you're cleaning out the grease? My intuition would be to try a synthetic motor oil, though wikipedia suggests that may pose harm to any brass or copper bits on the router and possibly a smoke/fire issue, esp w/ no speed control).
I got the idea of using WD40 from a guy that calls himself Robolop around different forums. He uses a manual router to make awesome stuff out of aluminium.
Here's one of his threads under a different name (Rossi 46 instead of his usual Robolop):
Aluminium frezen met bovenfrees
It is in Dutch but the pictures do say more than words...
After studying his Router model I must conclude my problem is probably speed related. He claims to use setting 2 on his router in this thread. That roughly translates to 10000 RPM. My router has a set speed of 22000.
So a RPM limiter would probably make sense.
~ Off to find an affordable solution 😀 ~
Are you dead set on using another sheet of aluminium for the last piece of the baffle?
If not, how about getting a sheet of transparent plexiglass? You would still get the color and feel of the alu panel underneath, but I know for a fact that a router cuts through plexiglass like butter!
If not, how about getting a sheet of transparent plexiglass? You would still get the color and feel of the alu panel underneath, but I know for a fact that a router cuts through plexiglass like butter!
ST KOOL 74 AL is a water soulable alum cutting oil that works good. Problem is youll need continous flow and lower rpms. My Dewalt DW618 I doubt goes slow enough for this unless going very slow. Removing the plastized alum burr from the surface edge helps reduce friction for a clean cut.
Id suggest a small submersable water pump for cooling fluid. Something on the 15-30 ltr per minute range should suffice. Cheap too 😉
Id suggest a small submersable water pump for cooling fluid. Something on the 15-30 ltr per minute range should suffice. Cheap too 😉
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