Alkyd Varnish vs Phenolic Varnish

[Cesar Vega]

I've tried to search for a side by side comparison of these varnishes, and I couldn't find a direct answer.

Could anyone elaborate a bit on the basic different on these type of varnishes?
I'm mainly interested in:
1) Sheen I could get from each one (gloss, satin, mate)
2) Rubbing out process for each

Thanks a lot :)

[Howard Acheson]

Using alkyd resin will result in a less amber tone. Typically it is mixed with linseed oil which imparts an amber tone. An alkyd resin/soya oil varnish will result in the least amber color.

Using phenolic resin in making varnish will result in a harder varnish and will end up with a rather dark amber tone. Phenolic resin is generally mixed with either linseed oil or tung oil. A phenolic resin/tung oil varnish is the most water and water resistant varnish.

Both alkyd and phenolic resin varnish are available in gloss and satin sheens. Both can be "rubbed" providing at least 3-4 weeks are allowed for curing (even longer is better). The phenolic resin varnishes will rub out somewhat better as the harder the varnish, the higher the gloss that can be achieved.

Keep in mind that the amount of resin to oil is a major factor in the resulting varnish. A higher percentage of resin to oil will result in a "short oil" varnish that will cure harder. A higher percentage of oil will result in a "long oil" varnish that will be more flexible but also more difficult to rub out. Typically, interior rated varnishes are short oil while exterior varnishes are long oil.

On a final note, "poly" or "urethane" varnishes are made by adding an amount of urethane resin to mixture. The is to make the resulting varnish more scratch, abrasion and heat resistant. At the same time it makes the varnish less water resistant because more oil is added to make the product more flexible. Because "poly" varnish is made to be more scratch resistant, rubbing to a high gloss is generally unsuccessful. Rubbing is scratching with abrasives. Poly is never any more glossy than it is right off the brush.

[Roger Benton]

Great question, thanks for asking.
Is there a list anywhere of which products are what type of varnish?
for example, who makes a short oil blo/alklyd product,
or a short oil tung/phenolic product?

[Cesar Vega]

Hi, Howard:

Thank you very much for your explanation.
It certainly sum up the topic very well.

I'm having a hard time to find alkyd resin based varnishes.
Seems the market is clogged with polyurethane all over the place!

I want to finish a couple of small computer desk, actually, they are more like tables.
The thing is, they already have a hand of a dark alcohol stain, and have not decided yet what to put on them.

I'm thinking polyurethane might be the right choice for these due the scratch resistant feature.





Using alkyd resin will result in a less amber tone. Typically it is mixed with linseed oil which imparts an amber tone. An alkyd resin/soya oil varnish will result in the least amber color.

Using phenolic resin in making varnish will result in a harder varnish and will end up with a rather dark amber tone. Phenolic resin is generally mixed with either linseed oil or tung oil. A phenolic resin/tung oil varnish is the most water and water resistant varnish.

Both alkyd and phenolic resin varnish are available in gloss and satin sheens. Both can be "rubbed" providing at least 3-4 weeks are allowed for curing (even longer is better). The phenolic resin varnishes will rub out somewhat better as the harder the varnish, the higher the gloss that can be achieved.

Keep in mind that the amount of resin to oil is a major factor in the resulting varnish. A higher percentage of resin to oil will result in a "short oil" varnish that will cure harder. A higher percentage of oil will result in a "long oil" varnish that will be more flexible but also more difficult to rub out. Typically, interior rated varnishes are short oil while exterior varnishes are long oil.

On a final note, "poly" or "urethane" varnishes are made by adding an amount of urethane resin to mixture. The is to make the resulting varnish more scratch, abrasion and heat resistant. At the same time it makes the varnish less water resistant because more oil is added to make the product more flexible. Because "poly" varnish is made to be more scratch resistant, rubbing to a high gloss is generally unsuccessful. Rubbing is scratching with abrasives. Poly is never any more glossy than it is right off the brush.

[Brian Hinther]

I believe Behlen's RockHard is a short oil BLO/phenolic resin varnish, and Waterlox is a short oil tung oil/phenolic resin varnish. Pratt & Lambert 38 is a soya oil/alkyd resin varnish.