Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines
Builds, Repairs, Show Your Machines! => Technical Tips, Builds, and Help => Topic started by: komet163b on March 22, 2023, 12:20:26 pm
-
Thanks Bruce, that is a great list.
If I'm in a pinch I can use it to pick
my poison.
As an occasional lapidary I have plenty
of experience with abrasive pastes for
shaping, for the most part, hard agates
and rutilated quartz. Grits from 240
to 100,000, anyone?
I have yet to try anything other than
the injection of steam oil into the valve.
I'll test that tonight. I could also
tighten the spring a bit like I did in the
S/V. I'd like to put off disassembling
the valve as it appears to be neccessary
to file the bottom of the shaft first.
That is a permanent change and a last resort
in my book.
Thanks,
Wayne
-
here is a list I found...
Relative Dentin Abrasivity (RDA) is a method of measuring the erosive effect of abrasives in toothpastes on tooth dentin. This value is necessary for FDA approval of the toothpaste but is usually not required to be disclosed on the label. In order to be FDA approved, the RDA must be 200 or lower. It is recommended to use a toothpaste with a RDA of 70 or lower. The lower the number, the less enamel/dentin will be worn away. The best way to know your toothpaste’s RDA is to ask the company. Here is a chart to help in understanding what the number means:
Table:
Low Abrasive: 0-70
Medium Abrasive: 70-100
Highly Abrasive: 100-150
Regarded as Harmful Limit: 150-250
This chart lists some common toothpastes that can be found in stores or online with their RDA value. This chart is courtesy of Kois Center located in Seattle, WA.
Abrasiveness Index of Common Toothpastes:
(RDA#- Toothpaste Brand Name)
0- Livionex
4- Toothbrush with Plain Water
7- Plain Baking Soda
8- Arm & Hammer (A&H) Tooth Powder
15- Weleda Salt Toothpaste
18.5- CariFree CTx4 Gel 1100/5000
18.5- CariFree CTx3 Gel
30- Elmex Sensitive Plus
30- Weleda Plant Tooth Gel
34- Pronamel
35- A&H Dental Care
40- Weleda Children’s Tooth Gel
42- A&H Metadent Advance Whitening
44- Squiggle Enamel Saver
45- Weleda Calendula Toothpaste
45- Weleda Pink Toothpaste with Ratanhia
45- Oxyfresh
48- A&H Dental Care Seneitive
49- Tom’s of Maine Sensitive
49- A&H Peroxicare Tartar Control
51- Crest with Scope
52- A&H Peroxicare Regular
52- Healthy Teeth & Gums
53- Rembrandt Original
53- Closys
54- A&H Dental Care PM Bold Mint
57- PerioSciences White Care
57- Tom’s of Maine Children’s
60- Biotene Gel
62- Clinpro 5000
62- Supersmile
63- Rembrandt Mint
65- Colgate Prevident 5000 Plus
65- Colgate Enamel Care Advance White
65- Crest with Scope Whitening
68- Colgate Regular
70- Colgate Total
70- A&H Advance White Sensitive
70- Colgate 2-in1 Fresh Mint
74- Crest Rejuvenating Effects Liquid Gel
75- Prevident 5000 Booster
79- Sensodyne
80- Aim
80- Biotene Paste with Fluoride
83- Colgate Sensitive Max Strength
91- Aquafresh Sensitive
93- Tom’s of Maine Regular
94- Rembrandt Plus
94- Plus White
95- Oxyfresh with Fluoride
95- Crest Regular
97- Oxyfresh Powder
100- Colgate Enamel Care Natural White
100- Colgate Optic White
101- Natural White
103- Mentadent
103- A&H Sensation
104- Sensodyne Extra Whitening
106- Colgate Platinum
106- A&H Advance White Extreme White
107- Crest Sensitivity Protection
109- Topex ReNew
109- Colgate Tartar Control w/ Baking Soda
110- Colgate Herbal
110- Amway Glister
113- Aquafresh Whitening
117- A&H Advance White Gel
117- A&H Sensation Tartar Control
117- Fluoridex Daily Defense
120- Close Up with Baking Soda
120- Crest Extra White w/ Tartar Protection
124- Colgate Whitening
126- Crest Maximum Sensitivity
130- Crest Extra Whitening
133- Ultra Brite
139- Crest MultiCare Fresh Mint
140- Crest Pro-Health
144- Crest MultiCare Whitening
145- Colgate Baking Soda Whitening
146- Ultra Brite Advanced White Formula
150- Pepsodent
155- Crest Rejuvenating Effects
165- Colgate Tartar Control
175- Colgate Luminos
200 -Colgate 2-in-1 Tartar Control/White
200- FDA Recommended Limit
250- ADA Recommended Limit
-
I think that Ultrabright has the most grit. You want the abrasive, not the bleach that most newer ones use.
-
I believe that Jensen used Crest toothpaste( or any toothpastes with whiteners) to lap the throttle in the bore, I have done this as well (for fine leak applications),but its a mess to clean out of there.
-
Thanks for the advice. I checked out the valve and
now realize that it can be raised just enough to get a
bit of steam oil in there without making a mess. I'll
find a hypodermic with a finer tip to ensure the oil
flows in as it may be a good way to get some oil into
the cylinder to start a run on any Jensen. So simple.
I'll do a follow up in a bit.
Thanks,
Wayne
-
Easiest thing I do is lift the valve slightly and put a drop of steam cylinder oil on it, then sort of twist it back and forth as it is pushed back down into its properly seated position. If it is really bad, I will use a bit of fine lapping compound to lap it into a better seat in the valve body. Don't know if I've ever had a Jensen steam valve that didn't leak at least a drop or three during a run, but you should be able to make it so it is not leaking a jet of steam.
Hope that helps.
-
Good afternoon from Brooklyn...
I have a Jensen 10 that runs pretty well now that
I have 'super-glued' the cylinder crack (mostly ok
now). It will build more pressure and power the light
better, but now it appears the steam line throttle is
spritzing away some of my precious pressure.
If anyone out there has cured this problem before,
please let me know how you did it. This is too nice
an engine setup for me to risk ham-fisting it.
Thanks,
Wayne